Opinion by
Mr. Chief Justice Bell,The Republic of Venezuela* (1) took an appeal, pursuant to the Act of March 5, 1925, P. L. 23 (12 P.S. §672 et seq.), from an Order of the Court below which decided it had jurisdiction of plaintiffs’ action of assumpsit, commenced by foreign attachment, and (2) filed in this Court an application petitioning this Court to issue a writ of mandamus or prohibition, or both, and dismiss plaintiffs’ action against it.
The principal question involved in each case is the legal effect of a Suggestion of Immunity made by the Department of State. The two actions were consolidated here and will be considered together in this Opinion.
Facts and Averments
Chemical Natural Resources, Inc.,** and Venezuelan Sulphur Corporation, C.A.*** sued Venezuela in an action of assumpsit commenced by a writ of foreign attachment which in this case is an action quasi in rem.**** Chemical is a Delaware Corporation of which not less than 50 percent of its stock is beneficially *138owned by United States citizens. Sulphur is a corporation organized under the laws of Venezuela and is a wholly owned subsidiary of Chemical.
On October 21, 1963, the plaintiffs (Chemical and Sulphur) commenced their action of assumpsit against Venezuela by filing a (praecipe for a) writ of foreign attachment (together with a complaint) under which writ the sheriff was directed to attach and seize the S.S. Ciudad de Valencia, allegedly the property of defendant Venezuela, which was then in the Port of Philadelphia and in the custody of Stockard Shipping and Terminal Corp.* The complaint demanded damages in the sum of $116,807,258.28.
On October 22, 1963, the day after the writ was issued, the sheriff attached and seized the steamship and took it into his possession. He also served copies of plaintiffs’ complaint on the ship’s master and on Stoekard as garnishee. However, two days later, on October 24, 1963, the attachment was dissolved without prejudice upon the order of plaintiffs’ attorney.**
Plaintiffs’ pertinent allegations in its amended complaint may be thus summarized:
In April of 1952 the plaintiffs, acting through Sulphur, purchased all mineral rights and interest or denouncements*** located in the Municipality of El Pilar, State of Sucre, Venezuela. Solely by reason of plaintiffs’ exploitation, reservoirs of mineral-laden geothermal steam were discovered in El Pilar. Subsequent*139ly, plaintiffs through Sulphur entered into several contracts with a department of the Venezuelan Government under which, inter alia, plaintiffs agreed to erect facilities for converting the steam into electrical power and defendant agreed to purchase the resulting power. Plaintiffs expended large sums of money in order to carry out their part of the contract. Thereafter, Venezuela unilaterally and without any justifiable cause cancelled the contract and confiscated plaintiffs’ property and property rights with a resulting loss to plaintiffs of over $116,000,000. Plaintiffs further averred that Venezuela operates its merchant vessels, including the ship which was seized, through a nationalized company wholly owned by Venezuela, and thus was engaged in a commercial and private or proprietary capacity as distinguished from a Governmental or public capacity. Plaintiffs further averred that they could not obtain Justice in any Venezuelan Court.
Venezuela has never entered a general appearance in this action, but improperly entered a special appearance for the purpose of challenging the jurisdiction of the Court of Common Pleas. However, Venezuela, more importantly and properly, challenged the jurisdiction of the Court by filing preliminary objections to plaintiffs’ complaint and writ of foreign attachment.* On December 5, 1963, Venezuela averred in its preliminary objections (a) that plaintiffs did not have a cause of action, and (b) that the Courts of Venezuela are available to the plaintiffs to assert any claim they may have, and (c) that the vessel allegedly operated by the nationalized Company is not, in fact, the property of Venezuela, and (d) that under the principle or doctrine of Sovereign Immunity the Court below could not ob*140tain jurisdiction through an action quasi in rem. Plaintiffs filed an answer which denied virtually all of Venezuela’s material averments of fact and conclusions of law.
Venezuela also sought and obtained the intervention of the United States Department of State which, by the United States Attorney for the Eastern District of Pennsylvania acting under orders of the Attorney General of the United States, filed a “Suggestion of Immunity”, which included a prayer to dismiss plaintiffs’ action, against Venezuela because of a certification of Sovereign Immunity which was recognized and allowed by the Department of State. The Attorney General acted upon a request received from the Legal Adviser of the State Department dated January 13, 1964 — after all parties had been wisely given a hearing by the Legal Adviser both on the facts and the law— reading pertinently:
“The Department recognizes and allows the sovereign immunity of the Republic of Venezuela, defendant in the above suit, from the jurisdiction of the Court of Common Pleas of Philadelphia County, Pennsylvania, and it will be appreciated if appropriate instructions can be issued to the United States Attorney in that jurisdiction to file a suggestion of immunity with the Court.”*
On December 18, 1964, the Court below entered the following Order: “In re the Suggestion of Immunity
“And Now, this 18th day of December, 1964, in re the Suggestion of Immunity, the motion of the defendant, the Republic of Venezuela, to dismiss the complaint is overruled, with leave to the defendant to file an answer within thirty days from date of this Order.”
What the Court apparently intended to do was to deny the State Department’s prayer and Venezuela’s motion to dismiss (which was contained in its prelimi*141nary objections), basing its denial on its determination that Venezuela was not entitled to Sovereign Immunity. Venezuela then took a timely appeal to this Court under §3 of the Act of March 5, 1925, supra.
Thereafter (on March 8, 1965), Venezuela, we repeat, filed in this Court a petition for a writ of mandamus or, in the alternative, a writ of prohibition, or both, naming as respondents Judges Milner and Ullinan. These Judges duly filed an answer opposing a grant of the writ and this Court ordered argument on the merits of the petition and answer at the time of oral argument on Venezuela’s appeal. Briefs, counter-briefs, supplemental briefs and reply briefs were filed by some or all of the parties in one or both of these cases and have been carefully studied by us.
Jurisdiction re Foreign Attachment
The Court below undoubtedly acquired jurisdiction by service of the writ of foreign attachment upon the captain of the vessel, and its jurisdiction was not subsequently divested or lost as a result of plaintiffs’ voluntary dissolution of the (foreign) attachment without prejudice. Cf. Ex Parte Peru, 318 U.S. 578 and Pa. R. C. P. 1272. For reasons hereinafter appearing we deem it unnecessary to decide whether on the present complicated and controversial record, with so many conflicting averments, Venezuela’s preliminary objections could be sustained. Cf. Pa. R. C. P. 1030 and 1017(b) (1) and 1028(c).
•Wé shall proceed to discuss the very important and crucial question of Sovereign Immunity which, we repeat, was raised (1) in Venezuela’s preliminary objections and (2) also in its petition for a writ of 'mandamus or prohibition or both, as well as in the State Department’s Suggestion of Immunity, and which the parties themselves consider the principal question in these cases.
*142Appeal
Venezuela’s appeal which., under the Act of 1925,* challenges the jurisdiction of the lower Court, cannot he sustained and must be quashed. It is important to note that the Order of the lower Court overruled Venezuela’s motion to dismiss the complaint “with leave to the defendant to file an answer within thirty days. . .”. This is an interlocutory Order,** and an appeal under the Act of 1925 raises only questions of jurisdiction, as that term has been interpreted and defined by the Courts. Vendetti v. Schuster, 418 Pa. 68, 208 A. 2d 864; see also University Sq. No. 1, Inc. v. Marhoefer, 407 Pa. 257, 180 A. 2d 427; Simpson v. Simpson, 404 Pa. 247, 172 A. 2d 168; McGinley v. Scott, 401 Pa. 310, 164 A. 2d 424; County Const. Co. v. Livengood Const. Corp., 393 Pa. 39, 142 A. 2d 9; Welser v. Ealer, 317 Pa. 182, 176 A. 429.
In the Vendetti case the defendant, a surgeon employed by the Government in a veterans hospital, moved to dismiss a malpractice suit brought against him by a patient on the ground that, as such surgeon he was immune from suit*** for negligent conduct. The lower Court dismissed his motion. This Court quashed the appeal, holding that the lower Court’s Order was interlocutory and was not appealable under the Act of 1925. In its Opinion the Court said (page 71) :
“Even if the defendant is in fact immune from suit as he contends, the Court below undoubtedly had jurisdiction of the cause of action**** because it has the jurisdiction and power to inquire into actions of trespass. In McWilliams v. McCabe, 406 Pa. 644, 179 A. *1432d 222, the Court said (page 648) : . . “. . . the test for determining whether a court has jurisdiction of the subject matter is the competency of the court to determine controversies of the general class to which the case presented for its consideration belongs, cmd the controlling question is whether the court had power to enter upon the inquiry, not whether it might ultimately decide that it was unable to grant the relief sought in the particular case. . . [citing numerous cases].’ ”
Sovereign Immunity is in the nature of an affirmative defense; (a) it does not go to jurisdiction and (b) it can be waived. For example, a Court unquestionably has jurisdiction (1) whenever a foreign Sovereign brings suit, and (2) whenever a foreign Sovereign interposes a set-off or counterclaim: National City Bank v. Republic of China, 348 U.S. 356; Mexico v. Hoffman, 324 U.S. 30; Guaranty Trust Compamy v. U.S., 304 U.S. 126. In such cases, a Sovereign cannot successfully challenge jurisdiction; indeed, the plea of Sovereign Immunity, even when pleaded by a Sovereign or by one of its corporations or instrumentalities, is not an absolute defense unless accompanied by the State Department’s Suggestion of Immunity: Mexico v. Hoffman, 324 U.S., supra (pp. 34, 35). As the Supreme Court in those cases (and in a number of other cases) stated, the question is not whether the Court had jurisdiction — which it had — but whether the jurisdiction which the Court had acquired should be relinquished for diplomatic reasons in order to promote our foreign relations or to prevent a possible war. Ex Parte Peru, 318 U.S., supra; Mexico v. Hoffman, 324 U.S., supra; Campania Espanola v. Navemar, 303 U.S. 68, 76; Sullivan v. State of Sao Paulo, 122 F. 2d 355, 360; Rich v. Naviera Vacuba S.A., 295 F. 2d 24; Stone Eng. Co. v. Petroleos Mexicanos, 352 Pa. 12, 42 A. 2d 57.
*144The contention that the question of jurisdiction is governed by our decisions in the NLRB cases is erroneous. In those cases, Congress has delegated to the NLRB exclusive jurisdiction in certain labor disputes, with the result that in cases involving such disputes (a) the field has been pre-empted by the Federal Government, and (b) State Courts have .no jurisdiction, and (c) Orders dismissing preliminary objections will be reversed: Terrizzi Beverage Co. v. Local Union No. 830, 408 Pa. 380, 184 A. 2d 243; Marine Engineers v. Interlake Co., 370 U.S. 173. For exceptions, see City Line Open Hearth v. Hotel M. & C.E., 413 Pa. 420, 197 A. 2d 614, holding that State Courts may restrain violence even when committed in such labor disputes.
Furthermore, the law is well established that jurisdiction of the subject matter cannot be conferred by waiver or by consent of the parties where no jurisdiction exists: Bell Appeal, 396 Pa. 592, 152 A. 2d 731; Seligsohn Appeal, 410 Pa. 270, 189 A. 2d 746.
It is clear, therefore, that in the instant case, the lower Court had jurisdiction, and an appeal under the Act of 1925 will not lie.
However, Venezuela, we repeat, filed in this Court a petition for mandamus and a petition for a writ of prohibition.
Mandamus and Prohibition
Under Section 3, Article V, of our State Constitution, this Court has been specifically granted original jurisdiction to issue writs of mandamus. addressed to Courts of inferior jurisdiction. On the other hand, writs of prohibition. are issued by this Court on the basis of its King’s Bench powers which it inherently possesses and which were specifically granted to the Court by the Act of May 22, 1722, 1 Sm. L. 131, and were confirmed and enlarged by §1 of the Act of June *14516, 1836, P. L. 784 (17 P.S. §41). Carpentertown Coal & Coke Co. v. Laird, 360 Pa. 94, 61 A. 2d 426; cf. also, Commonwealth v. Onda, 376 Pa. 405, 103 A. 2d 90; Commonwealth v. Caplan, 411 Pa. 563, 192 A. 2d 894.
In Carpentertown Coal & Coke Co., supra, the law pertaining to writs of prohibition was extensively reviewed. The Court held that the power to issue the prerogative writ of prohibition is an inherent power of this Court which was established by the first of the two Acts above mentioned, and was not taken away by the Constitution of 1874. The Court pertinently said (page 102) : “. . . The writ of prohibition is one which, like all other prerogative writs, is to be used only with great caution and forbearance and as an extraordinary remedy in cases of extreme necessity, to secure order and regularity in judicial proceedings if none of the ordinary remedies provided by law is applicable or adequate to afford relief. It is a writ which is not of absolute right but rests largely in the sound discretion of the court. It will never be granted where there is a complete and effective remedy by appeal, certiorari, writ of error, injunction, or otherwise: [citing cases]....”
In Commonwealth v. Caplan, 411 Pa., supra, the Court said (pages 567-569) : “Mandamus lies to compel a ministerial act [or mandatory duty] but not to ret view discretion, except where it is arbitrarily or fraudulently exercised or where it is based upon a mistaken view of the law: Garratt v. Philadelphia, 387 Pa. 442, 448, 127 A. 2d 738; Travis v. Teter, 370 Pa. 326, 330, 87 A. 2d 177; Maxwell v. Farrell School District Board of Directors, 381 Pa. 561, 566, 112 A. 2d 192.
“The procedure utilized to bring this case before our Court was inappropriate and therefore the writ of mandamus must be denied. . . . The Commonwealth should have petitioned this Court for a writ of prohibition.
*146..“The law is now well settled that the Commonwealth may petition this Court to restrain a lower Court from granting, discovery in a criminal case; While the cases are not in accord as to the extent or limitations- of a writ of prohibition,* this Court under our King’s Bench power has general supervisory and plenary power over all inferior tribunals: DiJoseph Petition, 394 Pa., supra [394 Pa. 19, 145 A. 2d 187]; Bell Appeal, 396 Pa. 592, 598, 152 A. 2d 731; Carpentertown Coal & Coke Co. v. Laird, 360 Pa. 94, 99, 100-101, 61 A. 2d 426; Bk. Comm. Vol. 3, *42. Cf. also Smith v. Gallagher, 408 Pa. 551, 185 A. 2d 135.
“For reasons above stated, the petition for a writ of mandamus is denied. However, because of the important issues presented in this case, we are staying all proceedings for 60 days in order to permit the District Attorney to petition this Court for a writ of prohibition.”**
Sovereign Immunity of Foreign Nations
It is a long and well established general rule that foreign Sovereigns, which cure duly recognized by appropriate action by the State Department, and their property are not amenable without their waiver or consent, to suit in the Courts of this Country. This widely accepted National and International diplomatic poli*147cy has been established among many civilized non-communist Nations on the principle of comity and for the preservation of International friendships and Peace. In order to preserve this policy of Sovereign Immunity from conflict, confusion and erosion, and to prevent a breach of friendly relations or a severance of diplomatic relations or a possible war with a foreign nation, the Supreme Court of the United States has held that in the realm of Foreign Relations or Foreign Affairs, a determination of Sovereign Immunity by the Executive branch of our Government, namely, the State Department, when conveyed to a Court through proper channels or officials, is — in the absence of waiver or consent — binding and conclusive upon all our Courts. If and when the State Department concludes that a foreign Nation is entitled to Sovereign Immunity that determination, we repeat, is conclusive no matter how unwise or, in a particular case how unfair or unjust the Department’s determination appears to be (a) to injured American citizens and (b) to vast numbers of the American people and (c) to our Courts: Ex Parte Peru, 318 U.S., supra; National City Bank v. Republic of China, 348 U.S., supra. See also to the same effect, Guaranty Trust Company v. U.S., 304 U.S., supra; Mexico v. Hoffman, 324 U.S., supra; The Schooner Exchange v. M’Faddon & Others, 7 Cranch 116; In re Investigation of World Arrangements, etc., 13 F.R.D. 280 (D.C., District of Columbia); Government of France v. Isbrandtsen-Moller Co., 48 F. Supp. 631 (D.C. S.D.N.Y. 1943); Sullivan v. State of Sao Paulo, 122 F. 2d, supra. See also Berizzi Bros. Co. v. S.S. Pesaro, 271 U.S. 562; Compania Espanola v. Navemar, 303 U.S., supra; Stone Eng. Co. v. Petroleos Mexicanos, 352 Pa., supra. Cf. also The Maret, 145 F. 2d 431, 440 (C.C.A. 3).
Ex Parte Peru, 318 U.S., supra, is factually similar and legally controlling. That case involved the *148libeling of the ship Ucayali belonging to the Republic of Peru to enforce a claim by a Cuban corporation arising out of the alleged breach (by a corporation acting for the Peruvian Government) of a charter party involving that ship. The case was commenced by a writ of prohibition filed in the Supreme Court of the United States after a lower Federal Court had refused to dismiss the libel, even after a Suggestion of Foreign Sovereign Immunity had been filed on behalf of the State Department. The Government of Peru asked for a dismissal of the action on the basis of a Suggestion of Immunity — filed (as in the case at bar) by the United States Attorney at the behest of the Attorney General, acting upon the request of the State Department which, in turn, was based upon a letter from the State Department’s legal adviser* — which therein had “recognized” Peru’s claim to Sovereign Immunity. The Supreme Court held (a) that the doctrine of Sovereign Immunity applied; (b) that Peru had not waived such immunity; (c) that upon submission of the State Department’s certification that it recognized Peru’s right to Sovereign Immunity “it became the court’s duty, in conformity to established principles, to release the vessel and to proceed no further in the cause.” (page 589). The Court pertinently said (pp. 579-580, 587-590) :
“This is a motion for leave to file in this Court the petition of the Republic of Peru for a writ of prohibition or of mandamus. The petition asks this Court to prohibit respondent, a judge of the District Court for the Eastern District of Louisiana, and the other judges and officers of that court, from further exercise of jurisdiction over a proceeding in rem, pending in that court against petitioner’s steamship Ucayali, and to direct the district judge to enter an order in the proceeding declaring the vessel immune from suit....
*149“On March 30, 1942, Galban Lobo Co., S.A., a Cuban corporation, filed a libel in the district court against the Ucayali for its failure to carry a cargo of sugar from a Peruvian port to New York, as required by the terms of a charter party entered into by libelant with a Peruvian corporation acting.as agent in behalf of the Peruvian Government. On April 9, 1942, the Republic of Peru, acting by the master of the vessel, intervened in the district court by filing a claim to the vessel, averring that the Republic of Peru was sole owner, and stating: ‘The filing of this claim is hot a general appearance and. is without prejudice to or waiver of all defenses and objections which may be available to respondent and claimant, particularly, but not exclusively, sovereign immunity.’
“On the same day, petitioner procured the release of the vessel by filing a surety release bond in the sum of $60,000, on which petitioner was principal. . . .
“This case presents no question of the jurisdiction of the district court over the person of a defendant. Such jurisdiction must be acquired either by the service of process or by the defendant’s appearance or participation in the litigation. Here the district court acquired jurisdiction in rem by the seizure and control of the vessel, and the libelant’s claim against the vessel constituted a case or controversy which the court had authority to decide. Indeed, for the purpose of determining whether petitioner was entitled to the claimed immunity, the district court, in the absence of recognition of the immunity by the Department of State, had authority to decide for itself whether all the requisites for such immunity existed — whether the vessel when seized was petitioner’s, and was of a character entitling it to the immunity. See Ex parte Muir, supra; The Pesaro, 255 U.S. 216; Berizzi Bros. Co. v. The Pesaro, 271 U.S. 562; Compania Espanola v. The Navemar, su*150pra. Therefore the question which we must decide is not whether there was jurisdiction in the district court, acquired by the appearance of petitioner, but whether the jurisdiction which the court had already acquired by seizure of the vessel should have been relinquished in conformity to an overriding principle of substantive law.
“That principle is that courts may not so exercise their jurisdiction, by the seizure and detention of the property of a friendly sovereign, as to embarrass the executive arm of the Government in conducting foreign relations. ‘In such cases the judicial department of this government follows the action of the political branch, and will not embarrass the latter by assuming an antagonistic jurisdiction.’ United States v. Lee, 106 U.S. 196, 209. More specifically, the judicial seizure of the vessel of a friendly foreign state is so serious a challenge to its dignity, and may so affect our friendly relations with it, that courts are required to accept and follow the executive determination that the vessel is immune. When such a seizure occurs the friendly foreign sovereign may present its claim of immunity by appearance in the suit and by way of defense to the libel. Compania Espanola v. The Navemar, supra, 74 and cases cited; Ex parte Muir, supra. But it may also present its claim to the Department of State, the political arm of the Government charged with the conduct of our foreign affairs. Upon recognition and allowance of the claim by the State Department and certification of its action presented to the court by the Attorney General, it is the court’s duty to surrender the vessel and remit the libelant to the relief obtainable through diplomatic negotiations. Compania Espanola v. The Navemar, supra, 74; The Exchange, 7 Cranch 116. This practice is founded upon the policy, recognized both by the Department of State and the courts, that our national interest will be better served in such cases if the wrongs *151to suitors, involving our relations with a friendly foreign power, are righted through diplomatic negotiations rather than by the compulsions of judicial proceedings.
“We cannot say that the Republic of Peru has waived its immunity. It has consistently declared its reliance on the immunity, both before the Department and in the district court. Neither method of asserting the immunity is incompatible with the other. . .
“The motion for leave to file is granted. We assume that, in view of this opinion, formal issuance of the writ will be unnecessary, . . .”
In National City Bank v. Republic of China, 348 U.S., supra, China sued the bank to collect a $200,000 deposit of the Shanghai-Nanking Railroad Administration which was an official agency of the Republic of China. The bank filed a counterclaim on the basis of China’s notes upon which it had defaulted in the amount of $1,634,432. China then pled sovereign immunity as a defense to the counterclaim; this defense was disallowed because by bringing the suit China- had waived the defense of sovereign immunity. Nevertheless, the Court speaking through Mr. Justice Frankfurter, said (pp. 358, 359) : “The status of the Republic of China in our courts is a matter for determination by the Executive and is outside the competence of this Court. Accordingly, we start with the fact that the Republic and its governmental agencies, enjoy a foreign sovereign’s immunities to the same extent as any other country duly recognized by the United States. See Guaranty Trust Co. v. United States, 304 U.S. 126, 137-138.
“The freedom of a foreign sovereign from being haled into court as a defendant has impressive title-deeds. Very early in our history this immunity was recognized, De Moitez v. The South Carolina, Bee 422, 17 Fed. Cas. 574, No. 9,697 (Admiralty Court of Pa., 1781, Francis Hopkinson, J.), and it has since be*152come part of the fabric of our law. It has become .such solely through adjudications of this Court. Unlike the special position accorded our States as party defendants by the Eleventh Amendment, the privileged position, of a foreign state is not an explicit- command of the Constitution. It rests on considerations of policy given legal sanction by this Court. ... It is idle-to repeat or rehearse the different considerations set forth in Mr.-Chief Justice Marshall's classic opinion in The Schooner Exchange v. M’Faddon, 7 Cranch 116.”
F. W. Stone Engineering Co. v. Petroleos Mexicanos, 352 Pa., supra, is likewise pertinent and controlling. That case was very similar to the case at bar. Plaintiff sued defendant, which was an instrumentality of the Mexican Government and wholly owned and controlled by that Government, in a foreign attachment proceedings and attached funds of the defendant which had been deposited and were in the possession of the Butler County National Bank & Trust Company. Defendant moved to dissolve the attachment and baséd its motion upon a communication from the Secretary of State to the Attorney General of the United States which recognized defendant as an instrumentality of Mexico. The letter from the State Department pertinently said: “Consequently, this Government recognizes and allows the claim of the Government of Mexico that Petroleos Mexicanos is immune from suit and its property from attachment.” The United States Attorney (acting upon the direction of the Attorney General pursuant to the request from the Department of State)' filed a “suggestion of Immunity.” Although the defendánt wás admittedly an instrumentality of Mexico and was engaged in a commercial enterprise fór profit)' this Court affirmed the Order of the lower Court which dissolved the attachment and said (pp. 16, 17, 18) :
“When the Department of State makes known its determination with respect to political matters growing *153out of or incidental to our Government’s relations with a friendly foreign state, it is the duty of the courts to abide by the status so indicated or created and to refrain from making independent inquiries into the merit of the State Department’s determination or from taking any steps that might prove embarrassing to the Government in the handling of its foreign relations. See Republic of Mexico v. Hoffman, 324 U.S. 30; Ex Parte Republic of Peru, 318 U.S. 578, 588-589; The Maret, 145 F. 2d 431, 440 (C.C.A. 3); Sullivan v. State of Sao Paulo, 122 F. 2d 355, 357-358 (C.C.A. 2).
“What was said in Ex Parte Eepublic of Peru, supra, at p. 589, is both apposite and controlling here: ‘The [State] Department has allowed the claim of immunity and caused its action to be certified to the . . . court through the appropriate channels. The certification and the request that the [property] be declared immune must be accepted by the courts as a conclusive determination by the political arm of the Government that the continued retention of the [property] interferes with the proper conduct of our foreign relations. Upon the submission of this certification to the . . . court, it became the court’s duty, in conformity to established principles, to release the [property] and to proceed no further in the cause’. The learned judge of the court below faithfully observed that injunction.”
See also Guaranty Trust Co. v. U.S., 304 U.S., supra. In that case, the United States as assignee of the Czarist Government sued Guaranty Trust Company to recover a $5,000,000 deposit. The bank was allowed to defeat the claim by pleading the statute of limitations, since Sovereign Immunity is an affirmative right or defense which may be asserted or consented to or waived as the Sovereign desires. However, the Court pertinently said (page 134) : “It is true that upon the principle of comity foreign sovereigns and their public property are held not to be amenable to suit in our *154courts without their consent. See The Exchange, 7 Cranch 116; Berizzi Bros. Co. v. S.S. Pesaro, 271 U.S. 562; Compania Espanola v. The Navemar, 303 U.S. 68....”
As the District Court of the United States for the District of Columbia aptly said in In re Investigation of World Arrangements, etc., supra (pp. 289, 291) : “A foreign sovereign is immune to suit, without its consent, in the Courts of the United States. . . .
“To cite a foreign sovereign into an American Court for any complaint against him in his public capacity is contrary to the law of nations. . . . There is the same necessity for reciprocal rights of immunity, the same feelings of injured pride, the same risk of belligerent action if government property is subsequently seized or injured. . . .”
Chemical and Sulphur (plaintiffs below and appellees here) first contend that The Schooner Exchange, Ex Parte Peru and the Stone cases are restricted and limited in their effect and do not apply to the case at bar because (1) procedurally those cases arose out of a seizure (by libel or writ of foreign attachment) of property of a foreign Government or of its instrumentality and that through appellees’ voluntary dissolution of the attachment without prejudice, this is no longer a “seizure” case and (2) consequently friendly foreign relations cannot be jeopardized by this suit. Appellees further contend that in spite of the release by them of the property seized, jurisdiction over the person of the defendant was obtained and still remains by way of the writ of foreign attachment, as well as by actual service of the writ and the complaint on the captain of Venezuela’s ship. Appellees’ attempted distinction of the Supreme Court cases previously cited in this opinion, and their aforesaid contentions are devoid of merit.
*155The principle or doctrine of absolute Sovereign Immunity has been attacked for many years by legal writers, by text authorities and by numerous Judges. The absolute doctrine is recognized by only a few countries in the world.* These authorities assert and appellees contend that even when Sovereign Immunity has been recognized and suggested by the State Department, the acceptance or rejection thereof is nevertheless a matter for the Courts — -whether the action be in rem, or quasi in rem or in personam — and the Courts in their sole discretion may accept or reject the plea of Sovereign Immunity. They further assert that this principle of absolute Sovereign Immunity should be restricted and should apply only to situations and activities in which the foreign Country is acting or is involved in its national or governmental or public capacity and not in a proprietary or a commercial or private or nongovernmental activity or capacity. However, where the State Department has (through appropriate channels) recognized the Sovereign Immunity of the foreign Country which is involved, and that Country has not waived its immunity or consented to the suit, the Supreme Court of the United States has never recognized this proposed restricted doctrine.
The Tate Letter
More importantly, appellees rely principally upon the so-called Tate Letter, which they contend (1) is the controlling law, (2) adopts the restrictive (foreign) Sovereign Immunity doctrine, and (3) allows American Courts in every ease to accept or reject a Suggestion (or plea) of Sovereign Immunity by a foreign government (a) acting through the State Department and its *156appropriate channels or (b) itself raising the issue. We shall quote the relevant parts of the Tate Letter, including the sentences which have caused confusion.
“United States Department of State — The
‘Tate Letter’ of May 19, 1952*
“Changed Policy Concerning the Granting of Sovereign Immunity to Foreign Governments.
“My Dear Mr. Attorney General:
“The Department of State has for some time had under consideration the question whether the practice of the Government in granting immunity from suit to foreign governments made parties defendant in the courts of the United States without their consent should not be changed. The Department has now reached the conclusion that such immunity should no longer be granted in certain types of cases. In view of the obvious interest of your Department in this matter I should like to point out briefly some of the facts which influenced the Department’s decision.
“A study of the law of sovereign immunity reveals the existence of two conflicting concepts of sovereign immunity, each widely held and firmly established. According to the classical or absolute theory of sovereign immunity, a sovereign cannot, without his consent, he wade a respondent in the courts of another sovereign. According to the newer or restrictive theory of sovereign immunity, the immunity of the sovereign is recognized with regard to sovereign or public acts (jure imperii) of a state, but not with respect to private acts(jure gestionis). ....
“The classical or virtually absolute theory of sovereign immunity has generally been followed by the *157courts of the United States, the British Commonwealth, Czechoslovakia, Estonia, and probably Poland.* . . .
“. . . The reasons which obviously motivate state trading countries in adhering to the theory with perhaps increasing rigidity are most persuasive that the United States should change its policy. Furthermore, the granting of sovereign immunity to foreign governments in the courts of the United States is most inconsistent with the action of the Government of the United States in subjecting itself to suit in these same courts in both contract and tort and with its long established policy of not claiming immunity in foreign jurisdictions for its merchant vessels. Finally, the Department feels the widespread and increasing practice on the part of governments of engaging in commercial activities makes necessary a practice which will enable persons doing business with them to have their rights determined in the courts. For these reasons it will hereafter be the Department’s policy to follow the restrictive theory of sovereign immunity in the consideration of requests of foreign governments for a grant of sovereign immunity.
“It is realized that a shift in policy by the executive cannot control the courts but it is felt that the courts are less likely to allow a plea of sovereign immunity where the executive has declined to do so. There have been indications that at least some Justices of the Supreme Court feel that in this matter courts should follow the branch of the Government charged with responsibility for the conduct of foreign relations.
. “In. order that your Department, which is charged with representing the interests of the Government before the courts, may be adequately informed it will he *158the Department’s practice to advise you of all requests by foreign governments for the grant of immunity from suit and of the Department’s action thereon.
“Sincerely yours,
“For the Secretary of State:
“Jack B. Tate,
“Acting Legal Adviser.”
(1) Does the Tate letter unqualifiedly express a new and restrictive policy, practice, and position of the State Department, viz., the Department will no longer recognize the absolute Sovereign Immunity of a foreign Nation, but merely a restrictive Sovereign Immunity; and (2) can the State Department privately change or abandon its policy in its sole discretion in each particular case; and (3) is the final determination a matter for the Courts or for the Department?*
Although the language of the Tate letter appears to be clear, its exact meaning has caused some confusion. The Tate letter, we repeat, states “For these reasons [the widespread practice on the part of governments of engaging in commercial activities] it will hereafter be the Department’s policy to follow the restrictive theory of sovereign immunity in the consideration of requests of foreign governments for a grant of sovereign immunity.
*159“It is realized that a shift in policy by the executive cannot control the courts but it is felt that the courts are less likely to allow a plea of sovereign immunity where the executive has declined to do so.”
The above quoted excerpts state in clear and unmistakable language that the Department has abandoned its long established principle of absolute governmental immunity and has for the hereafter adopted a new and restricted (restrictive) theory or principle of Sovereign Immunity, viz., absolute immunity does not apply to Governments when they are engaged in commercial activities. Furthermore, the Tate letter certainly implies —if indeed it does not clearly state — that the Department’s conclusion and suggestion of sovereign immunity “cannot control” the Courts which are free to make their own determination. This would undoubtedly very substantially change, if not nullify, the prior well settled law of this Country on the subject of Sovereign Immunity. Irrespective of its clear meaning, it appears that the State Department has silently abandoned the “revised and restricted policy” set forth in the Tate letter and has substituted a case by case foreign Sovereign Immunity policy, i.e., the State Department will recognize and suggest, or fail to recognize or grant or suggest Sovereign Immunity in each case presented to it, depending (a) upon the foreign and diplomatic relations which our Country has at that particular time with the other Country, and (2) the best interests of our Country at that particular time.
In Rich v. Naviera Vacuba, S.A., 295 F. 2d 24, 25-26 (C.C.A. 4, 1961), a Cuban ship had been libeled by an American corporation. In spite of Cuba’s hostile attitude and belligerent actions toward our Country, and the fact that the ship was engaged in a commercial enterprise, a Suggestion of Immunity was filed by the United States Attorney General at the request of our State Department. The Circuit Court (for the 4th *160District) sustained the Suggestion of Immunity and dismissed the libel. The Court rejected all the arguments therein made, which were repeated by appellees in this case, and said (pp. 25, 26) : “The vessel Bahia de Nipe sailed on August 8, 1961, from Cuba with a cargo of 5,000 bags of sugar destined for a Russian port. ...
“The libellants argue that before sovereign immunity. may be granted they should be heard by the court on whether the foreign government is in fact the owner and possessor of the property in question and, as to the ship, whether she was operated by that government not commercially but in a public capacity.
“Despite these contentions, we conclude that the certificate and grant of immunity issued by the Department of State should be accepted by the court without further inquiry. Ex parte Republic of Peru, 318 U.S. 578, 63 S. Ct. 793, 87 L. Ed. 1014. See also Republic of Mexico v. Hoffman, 324 U.S. 30, 65 S. Ct. 530, 89 L. Ed. 729; Compania Espanola De Navegacion Maritima, S.A. v. Navemar, 303 U.S. 68, 58 S. Ct. 432, 82 L. Ed. 667. We think that the doctrine of the separation of powers under our Constitution requires us to assume that all pertinent considerations have been taken into account by the Secretary of State in reaching his conclusion.”
Two individual claimants in the Rich case on September 9, 1961, petitioned the Supreme Court of the United States for a stay, on the ground that “. . . the suggestion of immunity had been issued in violation of the State Department’s policy as set forth in the Tate letter.” In response and in opposition to that application, the Solicitor General filed a Memorandum for the United States and said: “ ‘Similarly, the applicants’ reliance on the so-called “Tate letter” — dealing with the State Department’s policy towards foreign government-owned vessels operated in commercial or mercantile *161pursuits — is misplaced. That letter does set forth the considerations which the Department will take into account in determining whether or not to recognize a claim of immunity by a foreign sovereign. But it is wholly and solely a guide to the State Department’s own policy, not the declaration of a rule of law or even of an unalterable policy position; and, in addition, it sets forth only some of the governing considerations and does not purport to be all-inclusive or exclusive. Here, the State Department has, in fact, recognized Cuba’s claim to immunity, after taking into account all pertinent factors...'....”*
On September 11, 1961, Chief Justice Warren denied the application for a stay: “Application for stay denied. See Ex Parte Peru, 318 U.S. 578, and the Republic of Mexico v. Hoffman, 324 U.S. 30.”
It would appear from the Solicitor General’s aforesaid memorandum or brief and the aforesaid Order of Chief Justice Warren, that Ex Parte Peru and Republic of Mexico are still the law and that Sovereign Immunity when properly presented and not waived, is a matter for the conclusive determination of the State Department and not a matter for the Courts.
It is our conclusion, therefore, (1) that Sovereign Immunity of foreign Governments is a matter for determination in the first instance by the Executive Branch of the Government, namely, the State Department; and (2) if and when that Department’s determination has been made and has been appropriately presented to the Courts, the Department’s determination is binding and conclusive upon the Courts.
Appellees’ Other Contentions
We have examined (1) the Foreign Assistance Act *162of October 7, 1964,* and (2) the proposed official Draft of the Restatement of Foreign Relations Law, and (3) all the other authorities cited or quoted by appellees,** as well as- (4) many other authorities researched by us. We have considered all the contentions made by appellees and all the aforesaid authorities, and believe that this case does not fall within any exceptions to the general rule.
We believe that the decisions of the Supreme Court of the United States, and of this Court which are hereinabove quoted or cited control this case, and require this Court to grant the writ of prohibition prayed for by Venezuela.
Appeal of Venezuela quashed. A writ of prohibition is issued, directed to the Judges of the lower Court dissolving plaintiffs’ attachment ánd dismissing plaintiffs’ complaint.
hereinafter called Venezuela.
hereinafter called Chemical.
hereinafter called Sulphur.
As to an action quasi in rem, see Freeman v. Alderson, 119 U.S. 185, 187; Hamilton Equipment, Inc. v. Onamia Corp., 411 Pa. 525, 192 A. 2d 734; Fairchild E. & A. Corp. v. Bellanca Corp., 391 Pa. 177, 137 A. 2d 248; cf. also Falk & Co. v. South Texas Cotton Oil Co., 368 Pa. 199, 82 A. 2d 27.
hereinafter called Stockard.
The docket entries, both as recorded and as printed, erroneously state that by such order, “this suit is dissolved only without prejudice.”
Denouncement is defined in Black’s Law Dictionary, 3d ed., as meaning, in Mexican mining law, “an application to the authorities for a grant of the right to work a mine, either on the ground of new discovery or of forfeiture of the rights of a former owner through abandonment or illegal operation.”
See Pa. R. C. P. 1017(b); Williams Co. v. Pancoast Company, 412 Pa. 166, 170, 194 A. 2d 189; cf. also Monaco v. Montgomery Cab Co., 417 Pa. 135, 138, 208 A. 2d 252.
This has become the customary procedure.
Act of March 5, 1925, P. h. 23.
An appeal from some Orders which are not final is sometimes allowed by Statute.
Just like Venezuela’s claim to be immune in this suit.
Italics throughout, ours.
“To avoid further confusion we expressly overrule Commonwealth v. Mellon National Bank & Trust Co., 360 Pa. 103, 61 A. 2d 430.”
See the following cases where the writ of prohibition was issued: Special Grand Jury Case, 397 Pa. 254, 154 A. 2d 592 (1959); Philadelphia County Grand Jury Investigation Case, 347 Pa. 316, 32 A. 2d 199 (1943); Park’s Petition, 329 Pa. 60, 196 A. 495 (1938); McNair’s Petition, 324 Pa. 48, 187 A. 498 (1936); First Congressional District Election, 295 Pa. 1, 144 A. 735 (1928).
This, we repeat, is the customary procedure.
A compilation of the position of many foreign nations on the subject of absolute or restricted Sovereign Immunity is set forth in the so-called Tate letter which is hereinafter discussed.
(1960 A.M.C. 898-901 Dept. of State Bulletin, volume 26, page 984.)
Tate then enumerates and discusses the many Countries which have abandoned the absolute and adopted the restricted principle.
It should be noted that in all cases in which the State Department has not advised a Court of its determination of Sovereign Immunity, the determination thereof is properly a matter for the Court in the light of all the facts in that particular case: Republic of Mexico v. Hoffman, 324 U.S. 30; Berizzi Bros. v. S.S. Pesaro, 271 U.S. 562; Sullivan v. State of Sao Paulo, 122 F. 2d 355 (C.C.A. 2); Compania Espanola v. Navemar, 303 U.S. 68; Flota Maritima Browning De Cuba, Sociadad Anonima, v. Motor Vessel Ciudad de la Habana, 335 F. 2d 619 (C.C.A. 4, 1964) and Victory Transport Inc. v. Comisaria General de Abastecimientos y Transportes, 336 F. 2d 354 (C.C.A. 2, 1964); New York and Cuba M.S.S. Co. v. Republic of Korea, 132 F. Supp. 684 (S.D. N.Y. 1955).
1 International Legal Materials — Current Documents 1962-1963, pages 277, 288-89.
P. L. 88-633, §620(e)(2), 22 U.S.C.A. §2370(e).
Including one decision which constitutes the sole ease in which a Court has recognized an exception to the general rule where Sovereign Immunity had been determined by the State Department: Katingo Hadjipatera, 40 F. Supp. 846 (D.C. S.D. N.Y.); affirmed 119 F. 2d 1022 (C.C.A. 2).