Leo was disturbed throughout his pontificate by heresy and schism.
An investigation was begun in March 1559, and as the result of a conviction for heresy the exhumed body of Jorisz was burned, together with his portrait, on the 13th of May 1559.
This theory has advanced from the position of a disparaged heresy to acceptance by leading thinkers.
Called on the Christian princes to suppress the Albigensian heresy by force of arms, and for seven years the south of France was devastated by one of the most bloodthirsty wars in history, the Albigenses being slaughtered by thousands and their property confiscated wholesale.
The acts of councils of this age are full of the trials of bishops not only for heresy but for immorality and common law crimes.