Despite the assertions of several characters, Polycarp is never actually mentioned in Revelation, or anywhere else in the Bible. The chief sources of information concerning Polycarp are four: the authentic epistles of Ignatius of Antioch, which include one to Polycarp; Polycarp's own Epistle to the Philippians; passages in Irenaeus' Adversus Haeresis; and the letter of the Smyrnaeans recounting the martyrdom of Polycarp. However, Polycarp was known as a transmitter and authenticator of Revelation in a period when the gospels and epistles were just beginning to achieve acceptance.