What is the X in X-mas?
antipope from September 21 to December 15, 687.
pope from 642 to 649. Of Greek descent, he was noted for his generosity to the poor, though he had to devote most of his pontificate to combatting Monothelitism, a heresy maintaining that Christ had only one will, which continued to find favour in the East. Theodore refused to recognize the uncanonically installed patriarch Paul of Constantinople. Paul and his predecessor, Pyrrhus I, had relapsed into Monothelitism, for which Theodore excommunicated Pyrrhus in 648 and deposed Paul in 649.