Broxson, a Florida state prisoner serving concurrent sentences entered on pleas of guilty to robbery and attempted robbery, was denied habeas corpus relief in the District Court. As we stated in Busby v. Holman, 5 Cir., 1966, 356 F.2d 75, a plea of guilty, if voluntarily and understandingly made, is conclusive as to the defendant's guilt, admitting all of’the facts charged and waiving all non-jurisdictional defects in the prior proceedings against him. The threshold question, given the fact of a guilty plea, is whether the plea of guilty was voluntarily and understandingly made. Thus the sole question presented on this appeal is whether Broxson’s allegations form such a contrary basis as to warrant reversal for a hearing on the question of whether the pleas of guilty were coerced. All of the other errors asserted occurred prior to the pleas and may not now form the *945 basis for collateral relief until and unless the pleas of guilty are set aside.

We have carefully studied the application for writ of habeas corpus as well as the entire file and have reached the firm conclusion that the allegations, taken separately or in sum, fail to make out a basis for a hearing on the issue of coercion. The District Court did not err in denying the relief sought.

Affirmed.