Perseverance is sometimes a virtue and is often rewarded. “If at first you don’t succeed, try, try again” says the old copybook maxim. Joseph E. Young, the benefited defendant here, has beyond doubt practiced these principles. Litigation concerning his right to a.pension as the surviving spouso of a deceased policewoman pensioner now appears in this court for the third time, In Young v. O’Keefe, 246 Iowa 1182, *100769 N.W.2d 534, it made its first appearance. The basis of that suit was that the trustees of the policemen’s pension fund had denied his claim; there was an affirmance by the district court and by this court. We there held that “widowers” were not included in the statutory language defining those entitled to survivor’s pensions.
Thereupon the legislature, which can hardly be accused of lack of co-operation in Mr. Young’s efforts, amended the statutes applicable — sections 410.10, 411.1(10) and 411.6(13) — so that all “spouses” of deceased pensioners are included. See House Files 174 and 229, Acts of the Fifty-sixth General Assembly. This brought about the second attempt by Mr. Young. Again the trustees denied his claim, again the district court upheld them, and again, upon appeal, we affirmed. Young v. O’Keefe, 248 Iowa 751, 82 N.W.2d 111. Our decision was based upon two grounds: that the statutes as amended by the Fifty-sixth General Assembly were not retroactive; and if they were so construed the doctrine of res judicata would apply.
Again the legislature, acting as the Fifty-seventh General Assembly, tried a remedial measure. It enacted chapter 200, effective July 4, 1957, which we quote:
“Section 1. Section four hundred ten point ten (410.10), Code 1954, is amended by adding* a paragraph thereto as follows:
“This section and its provisions shall be interpreted for all purposes as including all surviving spouses whether such spouse existed at the time of the amendments to said section by the Fifty-sixth General Assembly or became such surviving spouse thereafter.”
Mr. Young then filed his third application for a survivor’s pension with the Board of Trustees, and on September 12, 1957, it was granted. The Woodbury District Court upon application of the City of Sioux City granted a writ of certiorari to review this holding of the board, but upon trial the writ was annulled and the action of the Board of Trustees upheld. The matter is now before us upon appeal by the city from this judgment.
I. We are first confronted with a matter of procedure. The defendant-appellee Young contends that the City of Sioux City has no right to bring an action against the Board of Trustees. The argument is that the board is an arm of the city, and a suit *1008by the city against it is in effect a suit by the city against itself; that it is actually attempting to act as both plaintiff and defendant, and under well-established rules of law and of logic this may not be done.
We find no merit in this contention. We think the argument is answered by holdings in State v. Bonzer, 68 N.D. 311, 279 N.W. 769, relied upon strongly by the appellee Young, who will hereinafter be referred to as the defendant. After stating the general rule that the same person cannot be both plaintiff and defendant in an action, the court said: “* * * this rule * * * does not apply where according to the actual interests involved the case does not amount to an action by one party against himself. * * * In the first place there is an actual controversy. * * * The State has no interest in this fund other than to see it is safely guarded and conserved and that those for whose benefit it is created receive their just dues.” 68 N.D., pages 315, 316, 279 N.W., pages 771, 772.
It is the duty of a city or town to levy an annual tax for the purpose of creating a pension fund. Section 410.1, Code of 1958. The Board of Trustees of the fund is set up by law, and its actions are not controlled by the city. Section 410.2, Code of 1958. But we think the city has the right, even the duty, to see that the fund, a large part of which is raised by taxes from the citizens, is administered and disbursed in accordance with law; and to this end it may bring an action to prevent illegal allowances and expenditures. 64 C. J. S., Municipal Corporations, section 2186(2), page 1030; Jersey City v. Hague, 18 N.J. 584, 115 A.2d 8; City of Philadelphia v. Wyszynski, 381 Pa. 153, 112 A.2d 327. It requires no extensive analysis of the situation here to know that the interests of the City of Sioux City on the one hand and of Young and the board on the other are not the same, and that an actual controversy is involved. Defendant’s position at this point is entirely lacking in merit.
II. We turn then to the substantial question involved. It may be stated thus: May the legislature by a later enactment direct the courts to give an interpretation to a statute different from the one which they have already applied to the same law in a ease involving the same claim, the same state of facts and the same parties? We think it clear that it may not.
*1009Qur opinion in the second Young v. O’Keefe case, 248 Iowa 751, 82 N.W.2d 111, answers every contention made by the defendant in the litigation now before us. It must be remembered that the facts are identical in the first two cases and this one. And all three cases affect the same parties, involve the same subject matter and determine the same cause of action. Hoover v. Iowa State Highway Commission, 210 Iowa 1, 8, 230 N.W. 561, 564, cited with approval in the second Young v. O’Keefe case, supra, at page 756 of 248 Iowa, page 114 of 82 N.W.2d. In the case in 248 Iowa, 82 N.W.2d, which we shall hereinafter designate as the second case, we were considering the effect of legislative amendments which changed the word “widow” to “spouse.” We there held that the amendments were not to be construed as retroactive, but prospective only, and so did not bring Mr. Young within their operation.
After we had so interpreted the amendments, the Fifty-seventh General Assembly, by enacting chapter 2001 of its Acts, attempted to change the nonretroactive construction we had put upon them. It said “This section [410.10, Code of 1954] * * * shall be interpreted for all purposes as including all surviving spouses whether such spouse existed at the time of the amendments to said section by the Fifty-sixth General Assembly or became such surviving spouse thereafter.” It must be the contention of the defendant here that the legislature thereby overruled our interpretation of the amendments made by the Fifty-sixth General Assembly, and that we are now bound to follow the legislative fiat. We do not agree. The legislature had a right to say whether its enactments were retrospective or prospective, as applied to future interpretations; it did not have the right to direct the courts how its statutes were to be construed with reference to matters already decided. We have construed the amendments made by the Fifty-sixth General Assembly as applied to a certain ease; the legislature may not, by later enactment, direct us to change our interpretation as it affects this same litigation. In Richardson v. Fitzgerald, 132 Iowa 253, 255, 109 N.W. 866, 867, we said: “* * * any direction by the Legislature that the judicial function shall be performed in a particular [certain] way is a plain violation of the Constitution.” Immediately following this, page 255 of 132 Iowa, page 867 of 109 *1010N.W., we quoted with approval from Cooley on Constitutional Limitations (7th Ed.) 114: “As the Legislature cmvnot set aside the construction of the law already applied by the courts to actual cases, neither can it compel courts for the future to- adopt a particular construction of a law which the Legislature permits to remain in force.” (Italics supplied.) We further said, at the same pages: “Expository legislation is so uniformly condemned by the courts that we need cite no more than a few of the numerous decisions with our approval of the principle. [Citing authorities] The Legislature may say what the law shall be, not what it is or has been * * To the same effect is Anderson v. Hadley, 245 Iowa 550, 559, 63 N.W.2d 234, 239, from which we quote: “* * * courts are not bound by the mere construction one legislature may put upon an act of a previous session. The interpretation of an existing statute is a judicial, not a legislative-, function. * * * The legislative intent that controls in the construction of a statute has reference to the legislature that enacted it, not a subsequent one.” To the same effect is Des Moines Independent Community School District v. Armstrong, 250 Iowa 634, 645, 646, 95 N.W.2d 515, 521, 522.
III. In fact, every point made by the defendant here to support his claim is denied by the opinion in the second case, in 248 Iowa-. We there held that the- statute changing “widow” to “spouse” was not retroactive. We are now confronted by a later legislative enactment saying we shall interpret it as retroactive. This comes clearly within the things the legislature may not do to control the decisions of the courts, as defined in the authorities cited and quoted from last above. We further said that if we should construe the amendments of the Fifty-sixth General Assembly as retroactive, “to do so would run into- the doctrine of res judicata.” Page 757 of 248 Iowa, page 115 of 82 N.W.2d.
We also said: “The spectre of res judicata arises to haunt plaintiff. The record conclusively establishes that his ease was already adjudicated when the statutory change occurred. He seeks here to establish the same status he sought before, by the same evidence. # * * If the purpose of res judicata be to add finality to judicial decision, the propriety of its presence here cannot be doubted. A judgment based on plain statutory con*1011struction, as was our earlier decision [246 Iowa 1182, 69 N.W.2d 534], would not be exactly final if the legislature could by subsequent retroactive (nunc pro tune) change of statute reopen the identical controversy for the benefit of a losing litigant.” 248 Iowa at pages 755, 756, 82 N.W.2d at pages 114, 115. Further pertinent language is this: “To accomplish it would require us to hold the amendment not only was not retroactive, but that it was sufficient to create a new right. The language will not bear that construction.”
"What we held in the second case, supra, was that the amendments made by the Fifty-sixth General Assembly were not retroactive; and that., if we should so construe them, the plaintiff’s claim would still be defeated by the doctrine of res judicata because it had been litigated and denied by the first case, Young v. O’Keefe, supra, 246 Iowa 1182, 69 N.W.2d 534. The amendment enacted by the Fifty-seventh General Assembly, supra, is a clear attempt, so far as this litigation is concerned, to direct us to consider the amendments of the Fifty-sixth General Assembly as retroactive, in reversal of our previous holding. This was beyond the power of the legislature, nor would it avail Mr. Young in any event; because we said in the second case that such a construction would merely result in a holding that he was barred by res judicata.
The defendant relies much upon Wagner v. Baron, Fla., 64 So.2d 267, 37 A. L. R.2d 831. We shall not attempt to analyze this case, further than to point out that the decision was by a court divided four to three, and that the reason given by one of the majority for his concurrence has little to do with the legal questions involved. To us, the reasoning of the minority seems sound. In any event, we think the ease at bar is ruled by the second Young v. O’Keefe case, supra. We cannot affirm the judgment of the trial court unless we abandon the reasoning of that case and overrule it. This we are not inclined to do. We there held the statute not retroactive, which determined the proper interpretation of it so far as Mr. Young’s claim is concerned. In addition, we now have two adjudications that he may not recover instead of one. As we said in the second ease, matters that have been decided by the courts may not be reopened by a *1012later legislative attempt to say that the construction put upon a statute must be changed for the benefit of a losing litigant.
The case is reversed and remanded to the district court with directions to sustain the writ of certiorari. All costs will be taxed against defendant-appellee Young, except that appellant will be allowed only $1.50 per page as cost of printing the record. —Reversed and remanded, with directions.
Garfield, Garrett, Oliver, Peterson, and Thornton, JJ., concur. Larson, J., concurs specially. Bliss and Hays, JJ., join in special concurrence.