Pope Gelasius I

Pope Gelasius I was the bishop of Rome from 1 March 492 to his death on 21 November 496. Gelasius was a prolific author whose style placed him on the cusp between Late Antiquity and the Early Middle Ages. Some scholars have argued that his predecessor Felix III may have employed him to draft papal documents, although this is not certain.

During his pontificate he called for strict Catholic orthodoxy, more assertively demanded obedience to papal authority, and, consequently, increased the tension between the Western and Eastern Churches. Surprisingly, he also had cordial relations with the Ostrogoths, who were Arians (i.e., had a different view on the nature of Jesus), and therefore perceived as heretics from the perspective of Nicene Christians.

Source: Wikipedia — https://en.wikipedia.org/wiki/Pope_Gelasius_I