Orton, C. J.
The same questions being in both these cases, they will be considered and disposed of together. They are brought before this court by a common-law writ of eertioi'ari, to review the proceedings in habeas corpus of *342the judge of the circuit court of Milwaukee county, by which the defendants in error were discharged from imprisonment. The pleadings in the habeas corpus and the certiorari proceedings show the following facts:
On the last day of the October term of the municipal court of Milwaukee county, 1893, the grand jury of said court found and returned true bills of indictment against the defendants and four other persons, under sec. 4541, E. S., for having fraudulently received deposits as directors of the Plankinton Bank of Milwaukee, knowing at the time said bank to be insolvent. The defendants were detained by virtue of commitments, on failure to enter into recognizance, issued out of said municipal court after their arraignment and pleas of not guilty. There was no grand jury summoned, selected, or impaneled for the said October term of said court, but the grand jury acting for said term, and which found said indictments, was the same grand jury duly impaneled for said court at and for the previous September term thereof. No order was made by said court directing a grand jury for said October term, and no grand jury was summoned for said term. The said grand jury’ was ordered, summoned, and impaneled for said September term by an order dated August 3,1893; and the said grand jury convened at the September term, on September 12, 1893, and entered upon the investigation leading to said indictments, but the same was not concluded during, the said September term, and for such reason they continued their sittings over and into the said October term, and until the last day of said term, when the said indictments were found and duly returned. On the last day of the September term the said court adjourned to October 2, 1893, which was the first day of the October term. The same grand jury found and returned several other indictments and against other persons during said October term.
On these facts the learned judge of the circuit .court dis*343charged the defendants, holding that said indictments were void, and that the said municipal court had no jurisdiction, therefore, to issue the writs for the arrest or the commitments for the detention of the defendants. I say that this was the ground upon which the defendants were discharged, because the want of jurisdiction in the municipal court was the only ground upon which the defendants could have been discharged on habeas corpus. Although this is made a question on this hearing, it is no longer an open question in this court. It has been repeatedly decided by this court that nothing less than jurisdictional defects in the proceedings can be considered or justify a discharge of the prisoner on habeas corpus; for errors and irregularities which do not go to the jurisdiction of the court may be inquired of on motion, appeal, or writ of error. The last paragraph of sec. 3428, R. S., provides: “ But no such court or officer on the return of any such writ [habeas corpus] shall have the power to inquire into the legality or justice of anj^ judgment, order, or execution,” etc. This is a limitation on the power of a judge or court to inquire of nothing less than jurisdictional defects in the proceedings on which the imprisonment is based. Mr. Justice Taylor, in State ex rel. Welch v. Sloan, 65 Wis. 647, so held after an examination .of the previous cases in this court, and cited People ex rel. Tweed v. Liscomb, 60 N. Y. 571-604; Ex parte Lange, 18 Wall. 163; Ex parte Gibson, 31 Cal. 628; Hurd, Hab. Corp. 327; In re Perry, 30 Wis. 268; In re Crandall, 34 Wis. 177; In re Semler, 41 Wis. 517; Hauser v. State, 33 Wis. 678. To these may be added In re Schuster, 82 Wis. 610; In re Graham, 74 Wis. 450; In re French, 81 Wis. 597.
We take it for granted that the learned judge of the court below held that the municipal court had no jurisdic-diction to issue the writs and commitments on which the defendants were arrested and imprisoned, on the ground that the indictments on which they were based were void, *344and that the indictments were void because not found by a lawful grand jury. The decision of the court below depended, then, on the legality of the grand jury that found the indictments. That question is supposed to be before us on this certiorari. But, as we understand the law, the court below had no right in this collateral .proceeding to inquire into the legality of that grand jury and decide it to have been an illegal body without authority to find the indictments; nor has this court the right to so inquire and decide. We are precluded from inquiring and determining whether the body of men that acted as a grand jury in finding the indictments was a grand jury de jure, by the barrier the law sets up to protect the acts of that body in the interest of the public and public justice as a grand jury defacto. “The de facto doctrine, which was introduced into the law as a matter of policy and necessity to protect the interests of the public where those interests were involved in the official acts of persons exercising the duties of an officer without being a lawful officer,” has its most salutary application to the acts of a grand jury and of other official instruments of the courts which constitute judicial proceedings. The courts are supposed to select and determine the qualifications of their subordinate official instruments necessary to the administration of justice. Their acts cannot be questioned without seriously affecting the proceedings of the courts and the conclusiveness of their judgments. The grand jury in question was summoned, selected, impaneled, and sworn for the September term of the court, and held its session and did business during that term. There is no question but that it wras a legal grand jury throughout the September term. On the last day of that term this same body adjourned, with the court, to the first day of the October term, and continued its unfinished business. It is contended that this body be-camefunctus officio as a grand jury on and after the last *345day of the September term. It was recognized by the court as a lawful grand jury, and the court received the indictments found by it, and finally discharged it from further service and ordered the payment of its fees. The legal grand jury of the September term simply held over its term. There cannot be a more appropriate application of the de facto doctrine than to such a body as a grand jury defacto while thus holding over and doing business in the October term of the court.
This doctrine, in its application to public officers and their acts, is well understood. Its history, object, and uses are exhaustively treated in the leading case of State v. Carroll, 38 Conn. 449. In People v. Petrea, 92 N. Y. 128, an indictment for grand larceny was found by a grand jury drawn under a void statute. It was insisted, on behalf of the defendant, that the grand jury was not a lawful one or within the requirement of the constitution. On behalf of the people it was contended “that it is sufficient to maintain the authority of the grand jury to investigate criminal charges and find indictments valid in their nature, that the body acted under the color of lawful authority".” The following cases are cited to this principle: People v. Dolan, 6 Hun, 232; Dolan v. People, 6 Hun, 493, 64 N. Y. 485; Carpenter v. People, 64 N. Y. 483; Thompson v. People, 6 Hun, 135; People v. Jewett, 3 Wend. 314; Cox v. People, 80 N. Y. 500; Friery v. People, 2 Keyes, 450; Ferris v. People, 31 How. Pr. 145. The court said: “ The objection to the constitution of the grand jury which found the indictment lies solely in the fact that they were drawn under the provisions of a void statute, etc. In all other respects the proceedings were regular. The jurors were drawn by the proper officer; they were regularly summoned and retained by the sheriff; they were recognized, impaneled, and sworn as grand jurors by the court, and as grand jurors they found the indictment; and rporeover, they were good *346and lawful men, duly qualified to sit as grand jurors. . . . The grand jury, although not selected in pursuance of a valid law, was selected under color of law and semblance of legal authority. ... An indictment was found by a body drawn, summoned, and sworn as a grand jury, before a competent court, and composed of good and lawful men. The jury which found the indictment was a de facto jury, selected and organized under tbe forms of law.” I cite largely from Judge Ajsdkews’ opinion, because it is in every respect applicable to the present case. In People v. Fitzpatrick, 66 How. Pr. 14, the indictment was found under a law void because unconstitutional. The above language in the Peirea Case was approved by the two judges, and the indictment was held good and valid, because found by a grand jury de facto. “ The grand jurors are public officers ” (Jac. Law Diet.; Toml. Law Diet.; 7 Bac. Abr. tit. “ Office AND Oefioees ”), and they are therefore within the common doctrine, and their acts should be held valid, as those of any other officer de facto. In People v. Dolan, 6 Hun, 232, it was not known liow or by whom the names of the persons summoned, sworn, and acting as grand jurors were drawn. The court said: “It is sufficient to maintain the authority of the grand jury to investigate criminal charges and find indictments valid in their nature, that the body acted under color of lawful authority.”
In In re Gannon, 69 Cal. 541, the grand jury organized in July, 1885, held over and was not dissolved by the court until March, 1886, notwithstanding a new grand jury had been selected and returned in January, 1886. A witness refused to testify before this old grand jury, on the ground that it was not a legal grand jury. He was imprisoned for contempt, and was seeking his discharge by habeas corpus. The court said: “As an organized grand jury, it would be competent to act under color of lawful authority. Having been appointed to office, and having taken the oath of *347office, the individual members are officers of the court, not only de jure but defacto; and their acts are valid so far as the public rights are concerned, although the title under which they performed those acts may be questionable. An indictment found bj^ a defacto grand jury is as regular as one found by a dejure grand jury.” In Ex parte Haymond, 91 Cal. 545, a witness refused to testify before the' grand jury on the ground that it was not a legal gi-and jury, and sought to be discharged from imprisonment on habeas corpus. The court said: “Without passing upon the question whether the grand jury before whom the petitioner was summoned to appear was impaneled in accordance with the provisions of the law relating to that subject, it is sufficient for us to say that such body has certainly a defacto existence.” In Dolan v. People, 64 N. Y. 485, and in Carpenter v. People, 64 N. Y. 483, the legality of the jury was challenged because illegally drawn by a commission under an unconstitutional statute, and the proceedings were sustained on the ground olde facto officers. In State v. Belvel, (Iowa) 56 N. W. Rep. 545, it is held that a grand jury composed of an.improper number maj’’ find a valid indictment. In Ex parte Springer, 1 Utah, 214, the indictment was for a capital offense, and the court said: “ The fact that the grand jury which found the indictment was illegal will not be considered upon the hearing of habeas corpus, as we conceive that we should stand upon the indictment.” In reason and by analogy a person under an ’indictment seeking his discharge on habeas corpus has the same right to allege that the judge or the clerk of the court is not lawfully judge or clerk as that the grand jury is not a legal grand jury. The several members of the grand jury are officers of the court, as we have seen, and their acts should be protected by the same principle that they are de facto jurors. In In re Burke, 76 Wis. 357, it was alleged that there was no office of judge to be filled by the incumbent, but it was held that the incumbent was judge de facto.
*348It would put an end to judicial proceedings if the legal title and qualifications of all judicial officers could be contested in collateral proceedings at the instance of aggrieved parties. This is a very important question, and a new one in this court. We have cited all the cases at hand, and from the high character of .the courts they ought to be considered not only satisfactory, but sufficient, especially when based upon such cogent and conclusive reasons. We hold, therefore, that the indictments found against the defendants are not void, but good and valid indictments, so far as this collateral proceeding is concerned, because found by a grand jury acting under color of lawful authority, and a good and sufficient grand jury defacto. It follows, also, that the municipal court of Milwaukee had jurisdiction to issue the writs by which the defendants were arrested, and the commitments upon which they were imprisoned, and therefore the judge of the circuit court had no cognizance of the cases to discharge the defendants.
By the Court.— The orders of the judge of the circuit court discharging the defendants are reversed, and the causes remanded with direction to remand the defendants to the custody of the sheriff of Milwaukee county.