This is an appeal by the Controller of the State of California from a judgment of the superior court, sitting in probate, which sustained respondent George Badovich ’s objections to the report of the inheritance tax appraiser and which fixed the inheritance tax on the estate of Jack B. Badovich, deceased.
The facts are not in dispute.
In 1934, when George Vukoye (now legally known as George Badovich) was 17 years of age, his natural parents entered into an oral agreement with the decedent, Jack B. Badovich, whereby George was to live with Jack who promised that he would consider George his son and would adopt him. George lived with Jack until Jack’s death in October, 1953, changed his name to George Badovich and was publicly acknowledged by Jack as his son and the heir to his estate. During the time George lived with Jack, he worked in Jack’s liquor store, conducted himself as a natural child and considered himself the son of Jack. Jack died intestate without having married or leaving issue of his body. He left no father or mother surviving him but did leave some blood relatives in Yugoslavia.* Jack had not, during his lifetime, instituted formal proceedings for the adoption of George.
On the death of Jack, the Citizens National Trust and Savings Bank of Los Angeles and Novak D. Novcie, a nephew of the decedent, were appointed as coadministrators of Jack’s estate. On June 14, 1954, George filed a petition in the probate proceeding to determine his heirship in the estate of Jack. After a hearing, Judge John Gee Clark made findings *119(which included the facts heretofore set forth) and concluded that ‘ ‘ George Eadovich occupies in equity the equitable status of an adopted son and by reason thereof is entitled to distribution of all of the Estate of the decedent.” A decree was then entered on the findings of fact to the effect that George had the equitable status of an adopted son of the decedent and was entitled to all of the estate (with the exception of the sum transferred to the relatives in Yugoslavia). Although the heirship proceeding was contested no appeal was taken and that decree is now final.
Subsequent to the decree of the probate court, an inheritance tax appraiser was appointed who filed his report claiming that George Eadovich was a stranger in blood to the decedent and that he should be allowed a specific exemption of $50 as a Class D transferee and computing the inheritance tax due at the rate of a stranger under sections 13310 and 13407 of the Eevenue and Taxation Code. The bank, Novak Novcic, and George filed objections to the report of the inheritance tax appraiser under section 14510 of the Eevenue and Taxation Code. A hearing was had before Judge Hansen who filed findings of fact, conclusions of law and a memorandum opinion and signed a judgment determining that George was a Class A transferee (adopted child). This appeal followed that judgment.
The only question involved here and one which is of first impression in this state is whether under the facts presented George is a Class A transferee. Section 13307 of the Eevenue and Taxation Code provides that a Class A transferee is “(b) A transferee whose relationship to the decedent is that of a child adopted by the decedent in conformity with the laws of this State, provided such child was under the age of 21 years at the time of such adoption.”
It is contended by appellant that since George was not adopted in conformity with the statutory requirements of this state that he takes as a stranger and only because of the contract made by his natural parents with the decedent. Eespondents contend that the heirship proceeding in which it was declared that George was, in equity, the adopted son of the decedent is a final judgment in rem which is binding on the appellant and all others. It is also argued by respondents that the words of the statute “adopted by the decedent in conformity with the laws of this state” (emphasis added) should be construed to mean not only in conformity with the *120statutory law of this state but the law as set forth by a decision of a court of competent jurisdiction. Respondents also argue that George took the money by inheritance-, that a stranger may not inherit; that it was only by reason of his inheritance that George is subject to an inheritance tax.
This court has held (Estate of Wise, 34 Cal.2d 376 [210 P.2d 497]) that the jurisdiction of the probate court is a jurisdiction in rem; that an heirship proceeding is not an ordinary civil action, but a specialized proceeding in rem. The res is the right of heirship and distribution and as to that issue the decree is binding on the whole world. We said there that “so it has been said that such heirship ‘decree [is] conclusive against all persons’ as the ‘basis for the decree of distribution which [is] to follow’ (Estate of Blythe, 110 Cal. 231, 234 [42 P. 643]); it settles ‘the rights of all persons claiming as heirs of the decedent, whether or not they are named in the complaint or personally served with summons’ (Title & Document Restoration Co. v. Kerrigan, 150 Cal. 289, 307 [88 P. 356, 119 Am.St.Rep. 199, 8 L.R.A.N.S. 682]). . . . The decree is not one ‘in personam in favor of one of the parties against another. ’ (Edlund v. Superior Court, 209 Cal. 690, 695 [289 P. 841].) Rather, as founded in a specialized proceeding in rem—‘not against persons as such, but against or upon the thing or subject matter itself’—the decree, when rendered, ‘is a solemn declaration of the status of the thing, and ipso facto renders it what the [decree] declares it to be.’ (11A Cal.Jur. § 73, p. 135, and cases there cited.) While it may ‘not be questioned that justice and sound policy require that the estates of decedents be distributed to persons rightfully entitled thereto and that every concern and endeavor of a probate court should be to the accomplishment of that purpose,’ that does not mean that a ‘valid decree’ determinative of rights ‘of distribution . . . when once final, may be disturbed at the behest of any rightful claimant, known or unknown, when the decree was rendered, for it is the well-settled policy of the law to preserve the inviolability of final judgments and decrees of courts of law and equity, and a valid decree of a court of probate partakes of the nature of such judgments. ’ (Edlund v. Superior Court, supra, 209 Cal. 690, 695.)” (See also 29 Cal.Jur.2d § 294, p. 273.)
Section 1908, subdivision 1, of the Code of Civil Procedure provides that the effect of a judgment or final order is as follows: “In case of a judgment or order against a specific *121thing, or in respect to the probate of a will, or the administration of the estate of a decedent, or in respect to the personal, political, or legal condition or relation of a particular person, the judgment or order is conclusive upon the title to the thing, the will, or administration, or the condition or relation of the person.” In Abels v. Frey, 126 Cal.App. 48, 53 [14 P.2d 594], it was held: “The jurisdiction of the probate court is a jurisdiction in rem, the res being the estate of the decedent which is to be administered and distributed with regard to the rights of creditors, devisees, legatees and all the world. (Warren v. Ellis, 39 Cal.App. 542 [179 P. 544]; Nicholson v. Leatham, 28 Cal.App. 597 [153 P. 965, 155 P. 98].) By giving the notice prescribed by the statute, the entire world is called before the court, and the court acquires jurisdiction over all persons for the purpose of determining their rights to any portion of the estate, and every person who may assert any right or interest therein is required to present his claim to the court for its determination. Whether he appears and presents his claim, or fails to appear, the action of the court is equally conclusive upon him, ‘ “subject only to be[ing] reversed, set aside, or modified on appeal.” ’ The decree is as binding upon him if he fails to appear and present his claim, as if his claim, after presentation, had been disallowed by the court. (William Mill Co. v. Lawler, 116 Cal. 359 [48 P. 323] ; Mulcahey v. Dow, 131 Cal. 73 [63 P. 158]; Hanley v. Hanley, supra [114 Cal. 690 (46 P. 736)].)” (See also Bath v. Valdez, 70 Cal. 350, 361 [11 P. 724] ; Barnard v. Wilson, 74 Cal. 512, 516 [16 P. 307]; Howell v. Budd, 91 Cal. 342, 349, 350 [27 P. 747].)
In the heirship proceedings, it was adjudged that George was entitled to inherit all of Jack's estate, and for the purposes of probating the estate he was adjudged to be in equity “an adopted son.” That determination has long since become final.
In Estate of Bloom, 213 Cal. 575, 580 [2 P.2d 753], it was held that the tax imposed by the Inheritance Tax Law is on the right to succeed to the property of the estate, rather than upon the property itself. (Estate of Letchworth, 201 Cal. 1 [255 P. 195].) The heirship decree adjudging that George was, in equity, the adopted son of Jack, and therefore entitled to succeed to his property, as an heir, was the basis for the imposition of the inheritance tax. Inasmuch as George takes Jack’s estate only by reason of the adjudica*122tion of Ms status as Jack’s adopted son and heir, it appears that appellant may not claim that he inherits as a stranger. The conclusion of the trial court sitting in probate as to George’s right to inherit as the adopted son of Jack may have been erroneous but it was an action in rem which is now final. In Estate of Daughaday, 168 Cal. 63 [141 P. 929], it was held that even if a decree establishing title under the McEnerney Act was mistaken in fact, it nevertheless stood as a conclusive adjudication in rem binding upon the whole world. In Woods v. Security-First Nat. Bank, 46 Cal.2d 697, 703, 704 [299 P.2d 657], where the plaintiff had instituted heirship proceedings and where the court’s decision had become final “long before the commencement of the present action,” we held that “Whatever reasoning prompted the court in arriving at its conclusion that the plaintiff was entitled to one-half is not now important. The court had the right to decide the question at issue, as the plaintiff in asserting that he was an heir was thereby claiming through the estate and not adversely to it. (Central Bank v. Superior Court, 45 Cal.2d 10, 16-17 [285 P.2d 906].) It mattered not whether the court sitting in probate found the property to be community or separate. It had the power to decide the question of heirship presented in the petition and the determination therein is res judicata.”
Appellant contends that the probate decree as to George’s right to inherit as an adopted son is not binding upon the- state inasmuch as the state could not have been a party to the heirship proceeding. Appellant’s argument that the state was not a proper party to the heirship proceeding is quite correct (Prob. Code, §§ 1080 et seq.) but it appears, also, that the appellant’s argument is inconsistent with its attempt to tax the inheritance here involved by classifying George as a stranger (Rev. & Tax. Code, § 13310). Section 13306 defines “transferee” as any person to whom a transfer is made, and includes any legatee, devisee, heir, next of kin, grantee, donee, vendee, assignee, successor, survivor, or beneficiary. Section 13307 defines Class A transferees as a husband, wife, lineal ancestor, or lineal issue of the decedent, or an adopted child, or a transferee to whom the decedent stood in the mutually acknowledged relationship of a parent for not less than 10 years prior to the transfer if the relationship commenced on or before the transferee’s fifteenth birthday, or the lineal issue of a child of the adopted child, *123or the mutually acknowledged child of the decedent. Section 13308 defines Class B transferees as the brother, sister, or descendant of a brother or sister of the decedent, or the descendant of a brother or sister of the father or mother of the decedent. Class D transferees are defined by section 13310 as any transferee who is not in any of the classes above mentioned. Since only an heir may inherit and since George was not a grantee, donee, vendee, assignee, or beneficiary of Jack, it follows that in view of the probate decree he took Jack’s estate as his adopted child and heir (§ 13307, subd. (b)) and appellant’s argument must fail.
Although no case directly in point has been cited to us, nor has independent research revealed any, it has been held in a proceeding under the act of 1889 which supplemented the Wright Irrigation Act, that the confirmation of the validity of an organization of an irrigation district and the bonds issued thereby was a proceeding in rem and that the judgment therein bound the whole world, including the state (People v. Linda Vista Irr. Dist., 128 Cal. 477 [61 P. 86]). (See also People v. Perris Irr. Dist., 132 Cal. 289 [64 P. 399, 773]; and 29 Cal.Jur.2d § 296, p. 276.) It has also been held (Brooks v. United States, 84 F.Supp. 622) that the decree of a California court of general jurisdiction which found that half of the community property was the property of the decedent and that the other half should be distributed to his surviving widow as her half, was binding on the Commissioner of Internal Revenue in determining plaintiff’s community interests. It clearly appears that since the inheritance tax to be levied depended in the first instance on the probate court’s findings as to heirship and George’s right to succeed to the property (Estate of Letchworth, 201 Cal. 1 [255 P. 195]), such finding must be binding on the state as well as on all others. We said in In re Miller, 31 Cal.2d 191, 199 [187 P.2d 722], in speaking of the Inheritance Tax Act of 1935, that “As with a succession statute, death is the ‘generating source’ for the operation of the inheritance tax, consistent with the commonly accepted theory that such tax is imposed on the right to receive a decedent’s property. (28 Am.Jur. §§ 9 and 10, p. 12.) While such tax is assessed upon the value of property so transmitted, the rates and exemptions are based upon the relationship of the recipient to the decedent. (28 Am.Jur. § 4, p. 9.) Accordingly, a cardinal purpose of the inheritance tax law would be to coordinate its assessment as closely as possible with the substantive pro*124bate law regulating the distribution of the decedent’s estate.”
It follows from what we have heretofore said regarding the conclusive nature of the decree with respect to the status of George in the heirship proceeding, that the judgment appealed from must be, and is, affirmed.
Gibson, C. J., Shenlc, J., Traynor, J., and Spence, J., concurred.
George agreed in writing to transfer and assign $55,000 of the estate to the blood relatives in Yugoslavia.