John Xvi.,, pope or antipope from 997 to 998, was a Calabrian Greek by birth, and a favourite of the empress Theophano, from whom he had received the bishopric of Placentia. His original name was Philagathus. In 995 he was sent by Otto III. on an embassy to Constantinople to negotiate a marriage with a Greek princess. On his way back he either accidentally or at the special request of Crescentius visited Rome. A little before this Gregory V., at the end of 996, had been compelled to flee from the city; and the wily and ambitious Greek had now no scruple in accepting the papal tiara from the hands of Crescentius. The arrival of Otto at Rome in the spring of 998 put a sudden end to the treacherous compact. John sought safety in flight, but was discovered in his place of hiding and brought back to Rome, where after enduring cruel and ignominious tortures he was immured in a dungeon.