Leo was disturbed throughout his pontificate by heresy and schism.
In the past many conflicting estimates were made of the character and achievements of the pope during whose pontificate Protestantism first took form.
Paul III., who had begun his pontificate with the intention of purifying the curia, was unaware of the grave danger in which Fisher lay; and in the hope of reconciling the king with the bishop, created him (loth of May 1535) cardinal priest of St Vitalis.
During his pontificate the church was brought to its lowest level of degradation.
Meanwhile, and throughout his long episcopate of thirty-two years, he foreshadowed the zeal and the enlightened policy later to be displayed in the prolonged period of his pontificate, building and restoring many churches, striving to elevate the intellectual as well as the spiritual tone of his clergy, and showing in his pastoral letters an unusual regard for learning and for social reform.