If at the outset Luther flung himself "prostrate at the feet" of the Papacy and owned its voice as the voice of Christ, the sentence of Leo no sooner confirmed the doctrine of Indulgences than their opponent appealed to a future Council of the Church.

In 1520 the rupture was complete.

A Papal Bull formally condemned the errors of the Reformer, and Luther publicly consigned the Bull to the flames.

A second condemnation expelled him from the bosom of the Church, and the ban of the Empire was soon added to that of the Papacy.

Charles the Fifth had bought Leo's alliance with himself and England by a promise of repressing the new heresy; and its author was called to appear before him in a Diet at Worms.