Pope Pius I was the bishop of Rome from c. 140 to his death c. 154,[1] according to the Annuario Pontificio. His dates are listed as 142 or 146 to 157 or 161, respectively.[2] He is considered to have opposed both the Valentinians and Gnostics during his papacy. He is considered a saint by the Catholic Church and the Eastern Orthodox Church[3] with a feast day in 11 July, but it is unclear if he died as a martyr.