Clement was the fourth Bishop of Rome — the third successor of Peter, after Linus and Anacletus. Tertullian places him as a direct disciple of Peter himself; Irenaeus writes that 'he had seen the blessed apostles, and had been conversant with them.'
Around the year 96, the church at Corinth was riven by a faction that had deposed its presbyters. Clement wrote to them in the name of the Roman Church — the Letter of Clement to the Corinthians, the earliest non-canonical Christian document we possess. In it he calls for the restoration of the deposed clergy, develops the doctrine of apostolic succession, and points to the natural and biblical order that ought to govern the Church. The letter was so authoritative that some early communities read it as Scripture.
Tradition holds that Clement was martyred under the emperor Trajan: exiled to a stone quarry in Chersonesus on the Black Sea, he so converted his fellow prisoners (and the local population) that the emperor ordered him drowned with an anchor tied around his neck. His relics were rediscovered, according to tradition, by Sts. Cyril and Methodius in the 9th century and brought to Rome.