He was an Apostolic father, meaning he was a student of one of the original disciples of Christ; and he was known to other important figures in the early Christian church, including Irenaeus, who knew him as a youth, and Ignatius of Antioch, his colleague in the Eastern Catholic church.

His surviving works include a Letter to the Philippians, in which he quotes the Apostle Paul, some of which quotes appear in the books of the New Testament and the Apocrypha. Polycarp’s letter has been used by scholars to identify Paul as the probable writer of those books.

Polycarp was tried and executed as a criminal by the Roman empire in 155 C.E., becoming the 12th Christian martyr in Smyrna; the documentation of his martyrdom is an important document in the history of the Christian church.