Brewer's: Apostolic Fathers
Christian authors born in the first century, when the apostles lived. John is supposed to have died about A.D. 99, and Polycarp, the last of the Apostolic Fathers, born about 80, was his disciple. These three are tolerably certain: Clement of Rome (30–100), Ignatius (died 115), and Polycarp (80–169). Three others are Barnabas, Hermas; and Papias. Barnabas was the companion of Paul, Hermas is a very doubtful name, and Papias (Bp. of Hierapolis) is mentioned by Eusebius.
Polycarp could hardly have been a disciple of John, although he might have received Christian instruction from the old “beloved one.”