delivered the opinion of the court:
On the hearing of the issues formed under a bill in chancery filed by the appellant, against appellees, to foreclose a mortgage on certain real estate in Saline county, the appellees, over the objection of the appellant, were permitted to introduce in evidence a decree entered in the circuit court of Saline county in a certain proceeding in chancery wherein the appellant was defendant and the grantor of appellee Fenwick was complainant, setting aside and declaring null and void the said mortgage sought by the appellant to be foreclosed herein and canceling the same as a cloud upon the true title.to said real estate. If the ruling of the court as to the admissibility, of such decree in evidence was correct, it is conceded the judgment of the Appellate Court here appealed from, affirming the decree entered by the circuit court dismissing the appellant’s bill for foreclosure, should be affirmed by this court.
The grounds of objection to the admissibility of the decree in evidence are, that the court which rendered it did not have jurisdiction of the subject matter of the proceeding or of the person of the defendant thereto. Jurisdiction of the person of the defendant to the proceeding was assumed on the theory the defendant was a nonresident of the State of Illinois and had been duly notified by publication, as required by the statute in such instances. The decree recited it appeared “to the court, from the affidavit on file, that said defendant is not a resident of the State of Illinois, and that his place of residence is not known and on due inquiry cannot be found.” The appellant offered in evidence the files in the cause wherein the decree in question was rendered, including an instrument filed by the complainant in the cause as an affidavit of the non-residence of the defendant therein, the appellant here. As to this instrument counsel for appellant, in their brief, say: “The affidavit *238of non-residence is wholly void. It was sworn to before a notary public in Allen county, Ohio, and the notary does not state in his certificate that he is authorized, under.the laws of the State of Ohio, to administer oaths.” i The power to administer an oath is not incidental to the office of notary public. If possessed by a notary it is by force of the enactments of the State under which he holds his commission. (Trevor v. Colgate, 181 Ill. 129.) The enactments of a sister State may be proven by printed statute books purporting to be printed under the authority of such State, (Rev. Stat. sec. 10, chap. 51, entitled “Evidence and Depositions,”) and the true meaning or construction of the statute of a foreign State, as declared by the courts of last resort of such State, may be proven by books of reports of decisions of such courts purporting to be published by authority, (chap. 51, sec. 12,) or by the testimony of witnesses learned in the law of such State. Hoes v. VanAlstyne, 20 Ill. 202.
The court found and recited in its decree that it appeared from an affidavit on file the defendant was not a resident of the State, etc. An affidavit is a declaration in writing signed by an affiant and sworn to by such affiant before some person who has lawful authority to administer oaths. (Harris v. Lester, 80 Ill. 307.) The finding of the court therefore involved consideration and judicial determination of the question of the authority of the notary public to administer the oath to the affiant. The decree was rendered by a court of general jurisdiction and the atta.ck upon it is made in a collateral proceeding. In such instances, in the^absence of proof to the contrary, nothing is presumed to be outside the jurisdiction of the court which rendered the decree. (Swearengen v. Gulick, 67 Ill. 208.) Service by publication was relied on to acquire jurisdiction of the person of 'the defendant in that proceeding. In determining as to the existence of facts necessary to constitute service by publication the court had lawful power to receive parol or *239documentary testimony. (Botsford v. O'Conner, 57 Ill. 72; Barnett v. Wolf, 70 id. 76; Swift v. Yanaway, 153 id. 197; Bickerdike v. Allen, 157 id. 95; Reedy v. Camfleld, 159 id. 254.) It is not necessary, in answer to a collateral attack, testimony received for that purpose should be preserved in the record, for the reason the legal presumptions arise in aid of the jurisdiction of the court that competent evidence was produced to warrant the finding the instrument in question was an affidavit, within the legal meaning of that word. (Bickerdike v. Allen, supra; Reedy v. Camfleld, supra.) The rule to be deduced from the decisions of this court on the point is, that the findings of a court of general jurisdiction as to jurisdictional facts necessary to constitute service by publication are conclusive as against collateral attack unless such findings are irreconcilable with facts otherwise disclosed by the record, and that in aid of such finding and in aid of any apparent conflict in the record it will be presumed evidence was heard to support the finding in all cases where it is competent to receive evidence for that purpose.
The bill on which the decree here assailed is founded, prayed a decree canceling the mortgage which appellant in this proceeding seeks to foreclose, as a cloud on the title of the complainant in the bill, but it was not averred in the bill that the complainant had possession of the land or that it was vacant and unimproved. We have repeatedly held it is essential to the right of a complainant to maintain a proceeding in chancery to remove a cloud on the title to real estate, that it should be alleged in the bill and proved upon a hearing the complainant had possession of the land or that it was vacant and unoccupied. The appellant insists that in view of these holdings and of the lack of averment in the bill upon which the decree is founded, the court was lacking in jurisdiction of the subject matter to render the decree.
The jurisdiction of courts of equity to remove a cloud from title to real estate is of common law origin. (2 Am. *240& Eng. Ency. of Law, 309.) Jurisdiction of the subject matter of a proceeding is conferred by law. The power to decide any particular case of the subject matter whereof the court has jurisdiction is conferred by the pleading. If the court has jurisdiction of the subject matter of a real cause of the character of the one attempted to be set forth in the pleading, it has jurisdiction of the subject matter of the controversy and judicial power to determine whether the case made by the pleadings is one within its jurisdiction. In Bostwick v. Skinner, 80 Ill. 147, we quoted with approval the remarks of Mr. Justice Allen in cox v. Thomas, 9 Gratt. 323, as follows (p. 153): “The only question would seem to be whether the subject matter was within the jurisdiction of the court. If it was,—if the jurisdiction of the court extended over that class of cases,—it was the province of the court to determine for itself whether the particular case was one within its jurisdiction.” In People v. Seelye, 146 Ill. 189, we said (p. 221): “If a court has jurisdiction of the subject matter and the parties, it is altogether immaterial, where its judgment is collaterally called in question, how grossly irregular or manifestly erroneous its proceedings may have been; its final order cannot be regarded as a nullity, and cannot, therefore, be collaterally impeached. * * * The court is invested with power to determine the rights of the parties, and no irregularity or error in the execution .of the power can prevent the judgment, while it stands unreversed, from disposing of such rights as fall within the legitimate scope of its adjudication.” The author of the article entitled “Jurisdiction,” in 12 Encyclopedia of Pleading and Practice, (p. 129,) remarks: “But as a general proposition, jurisdiction of the subject matter is conferred by law, and does not rest upon averments in pleadings nor is affected by error in sustaining a pleading, and if the pleadings contain sufficient matter to challenge the attention of the court, and such a case is thereby presented as to authorize the court to delib*241erate and act, it is sufficient for the purpose of conferring jurisdiction."
The circuit court of Saline county, in chancery sitting, had jurisdiction of the subject matter of the proceeding in which the decree in question was rendered,—that is, it had jurisdiction of that class of cases wherein decrees may be lawfully rendered removing clouds from titles. It had jurisdiction and power to judicially consider and determine whether the case as disclosed by the bill entitled the complainant in the bill to relief of that character. That it fell into error in the exercise of its jurisdiction and power could' not operate to deprive it of jurisdiction to act. An error in the exercise of jurisdiction cannot be urged to impeach its decree in a collateral proceeding. Having complete jurisdiction of the persons and of the subject matter it was clothed with lawful, power to act, and its action, however erroneous, must be regarded as valid and binding in every collateral proceeding. (Hobson v. Ewan, 62 Ill. 146; Wenner v. Thornton, 98 id. 156.) “When jurisdiction has once attached, the court has a right to decide every question arising in the case, and errors of judgment or irregularities, however gross, which do not render the* judgment absolutely void, are not available on collateral attack, but the judgment is valid until reversed or vacated bv direct proceeding.” 12 Encv. of Pl. & Pr. 197.
The judgment of the Appellate Court must be and is affirmed.
T 7 . „ , Judgment affirmed.