delivered the opinion of the court.

Upon this application for supersedeas, the question presented is whether the trial court committed error in refusing to vacate a default judgment taken against plaintiff in error.

The action was against both plaintiff in error and his wife Anna Redeker, to recover the sum of $590, the unpaid balance of the purchase price of a player piano sold to Anna Redeker by the music company. She was sued on her note, the husband under the family expense statute. Service was made on her personally at her home *372 in Denver, September 20, 1927; and at tbe same time copies of tbe summons and complaint were left witb ber for tbe plaintiff in error. Neither defendant having appeared in tbe action, judgment was taken against both, November 8,1927. November 12, 1927, plaintiff in error filed bis application to vacate tbe judgment and to be allowed to file an answer, which be tendered, denying tbe allegations of the complaint. November 28, 1927, the coqrt denied the application.

Tbe application was based upon section 81, Code of 1921. Because tbe summons was not left with him personally plaintiff in error asserts that bis application is covered by tbe concluding paragraph of that section, providing for relief from default judgment at any time within one year where tbe defendant is not “personally served. ” It is not necessary for us to determine whether or not tbe plaintiff in error was “personally served” within tbe meaning of section 81, since it is settled that, even in cases of constructive service, the application for leave to answer after default taken is addressed to tbe sound discretion of tbe trial court. Fullen v. Wunderlich, 54 Colo. 349, 130 Pac. 1007; Donald v. Bradt, 15 Colo. App. 414, 62 Pac. 580; Hollingsworth v. Ring, 26 Colo. App. 121, 141 Pac. 139.

Tbe sole inquiry therefore is whether or not tbe refusal of tbe trial court to vacate tbe default judgment constituted an abuse of discretion.

The matter was determined upon tbe verified application, no counter affidavit being filed, nor any evidence taken. Tbe application states that the judgment was procured “in violation of an agreement which tbe plaintiff bad witb tbe attorney for tbe wife of Frank H. Redeker, tbe other defendant in this case.” No particulars of tbe alleged agreement are given, nor is it shown why plaintiff in error was entitled to rely upon it. Clearly, this ground was insufficient. Barra v. People, 18 Colo. App. 16, 69 Pac. 1074; Union Co. v. Cooper, *373 15 Colo. App. 65, 60 Pac. 946. The application further states that service on plaintiff in error was secured solely by substituted service on Anna Redeker, “that petitioner was never notified and never knew of said service and never knew of said suit being brought and had no knowledge of this action or proceeding until after the judgment was secured in the above cause, on to wit the 8th day of November, A. D. 1927, * * * that after said judgment had been secured, he then first learned of the institution of said suit and of judgment being entered.”

If in fact a defendant upon whom substituted service is obtained, is, without his connivance, not apprised of the service, and remains in ignorance of the pendency of the action until after the judgment is entered, and then applies promptly to have it set aside, refusal to grant him that relief would appear arbitrary. But in the circumstances of this case we cannot say that the trial court was bound to accept as true the statement of plaintiff in error, that he did not learn of the institution of the suit until after judgment was entered. Copies of the summons were left for him at his home with his wife. His application offers no explanation whatsoever of her failure to deliver the copies to him or to advise him of the institution of the action. He did not produce her affidavit nor explain his inability to procure it. It does not appear that any estrangement or separation had occurred in the interim. The burden was upon him to establish the existence of the grounds on which he relied for relief, by clear, strong, and satisfactory proof. 34 C. J. 358, Fullen v. Wunderlich, supra; Donald v. Bradt, supra; Anderson v. Lazarowitz, 142 N. Y. S. 304. We cannot hold, as we would be compelled to do in order to reverse this judgment, that the affidavit of a defaulted defendant upon whom substituted service had been obtained, that he did not learn of the institution of the suit until after the judgment was taken, compels the trial court to grant *374 bim relief although he offers no explanation as to why the substituted service failed of the purpose which the law presumes it will accomplish.

The application for supersedeas is denied, and the judgment is affirmed.