The appellant, some time prior to December 21, 1917, brought suit for divorce in the county court of Teller county, Colorado, from his wife, Lena B. Groves, who appeared in that action and filed an answer and cross-complaint. After a hearing or hearings had been had, the defendant therein appeared *113in court with her attorney, and in the absence of the plaintiff and his attorney, procured the entry of a decree upon her cross-complaint in her favor, which awarded the custody of the child of the parties to Mary E. Barto, the mother of the defendant, then and now residing in Bellingham, in this state, until the further order of the court. The husband soon learned of the entry of the decree, paid the alimony by it awarded, and knew of the wife’s intention to bring the child to Washington for the purpose of placing it in the care of Mrs. Barto, and assisted in that purpose by advancing money for traveling expenses. The decree became final under the Colorado law on June 21, 1918, and thereafter, in December, 1918, after the child and its mother were domiciled in this state, the appellant sought and obtained a modification of the decree in the court where it was entered, by the terms of which the custody of the child was awarded to him. Some notice of this application for modification was served upon the respondents in this state, hut neither of them made any appearance in response thereto.

After the child had been in this state about a year, ánd after the modification of the decree of the Colorado court, as above mentioned, the appellant, armed with such modified decree, came to Washington, personally called upon Mrs. Barto, and demanded possession of the child. The demand being refused, he made application to the trial court for a writ of habeas corpus to secure such possession. Mrs. Barto made answer and return to .the writ, and the child’s mother, Lena B. Groves (now Lena B. Ridge) appeared, was made a party and defended, without objection. From a decree awarding the child to the mother, this appeal is prosecuted.

It is contended here that, under the rules of comity existing between the courts of the several states, and *114the full faith and credit clause of the Federal constitution, the trial court was bound by the modified decree of the Colorado court; and that, in any event, under the evidence introduced, the custody of the child should have been awarded to the father. Cases are not wanting which hold that a decree of divorce awarding the custody of a child or children is not only res judicata in the state where entered, but elsewhere, so far as the parties to the original action are concerned, but this rule is not applicable here, because the modification of the decree was based upon substituted service without the state, made after both the mother and child had become domiciled in Washington. The weight of authority is to the effect that, when the child has become domiciled in another state, the courts of the place of domicile may, at the least, determine the custody of such child as its welfare may demand, in all cases where there are shown changes of conditions arising subsequent to the entry of the original decree. In re Alderman, 157 N. C. 507, 73 S. E. 126, 39 L. R. A. (N. S.) 988; Mylius v. Cargill, 19 N. M. 278, 142 Pac. 918, Ann. Cas. 1916B 941, L. R. A. 1915B 154; Nelson, Divorce and Separation, § 980; 9 E. C. L., § 293.

So here, while appellant claims that the original decree was entered in his absence, and contrary to an understanding that the wife should have a divorce while he should be given the custody of the child (which understanding is denied), yet he had knowledge of the decree before the child and its mother had left the jurisdiction of the court, and if he or the court had been imposed upon, it would seem that it was then his duty to ask that the decree be modified; yet he did nothing looking towards such a modification, permitted and assisted in the child’s removal from Colorado and acquiesced for nearly a year, and when he made his application for modification, the in*115terested parties were beyond the jurisdiction of the Colorado court, and the showing upon which the modification was made was an ex parte one, of which we have no knowledge, and it should not be binding upon the courts of this state, where the child was domiciled at the time it was made. Seeley v. Seeley, 30 App. D. C. 191, 12 Ann. Cas. 1058; Milner v. Gatlin, 139 Ga. 109, 76 S. E. 860.

In any event, a change of conditions is set up in Mrs. Barto’s return to the writ which was sufficient to justify the trial court in hearing the case on its merits. Going, then, to the merits, we find no little difficulty in determining what are the facts. Everything testified to on the one side is squarely denied upon the other. Appellant attempted to show that both the mother and Mrs. Barto are unfit to have the child. As to the latter, the testimony is not sufficient to warrant any attention, while as to the former, the evidence is confined almost wholly to matters which occurred and were within the knowledge of appellant at and before the time the original decree was entered, and should-have been proven, if susceptible of proof, while the Colorado court had jurisdiction of the person of the defendant in that action. The original Colorado decree being silent on all such matters, we are not now disposed to inquire into the conduct of the mother before the entry of that decree. It does appear that the mother has remarried since coming to Washington, has now a fit and comfortable home for the child and is financially -able to provide for her wants; and the trial court, who heard and saw the witnesses, was of the opinion that, considering the tender age of the child, now about five years old, its welfare would be best subserved by awarding it to the mother for the time being, and that, if the mother’s home and influence should later prove to be what the father feared, *116the way would be open under the laws of, this state for a subsequent inquiry.

Finding no error, the judgment is affirmed.

Holcomb, C. J., Bridges, Mount, and Fullerton, JJ., concur.