Pope Anastasius I (died 19 December 401) was Pope from 27 November 399 to his death in 401.
He was born in Rome, the son of Maximus. He condemned the writings of the Alexandrian theologian Origen shortly after their translation into Latin. He fought against these writings throughout his papacy, and in 400 he called a council to discuss them. The council agreed that Origen was not faithful to the Catholic Church.
If Origen has put forth any other writings, you are to know that they and their author are alike condemned by me. The Lord have you in safe keeping, my lord and brother deservedly held in honour.
During his reign he also encouraged Catholics in North Africa to fight Donatism. He instructed priests to stand and bow their head as they read from the gospels. Among his friends were Augustine, Jerome, and Paulinus. Jerome speaks of him as a man of great holiness who was rich in his poverty. The New Testament canon as it is now was first listed by Athanasius in 367, in a letter written to his churches in Egypt, Festal Letter 39.