Any of certain teachers and writers of the early Christian church, eminent for their learning and orthodoxy, experience, and sanctity of life. They lived between the end of the 1st and the end of the 7th century, a period divided by the Council of Nicaea 325 into the ante-Nicene and post-Nicene Fathers.
The ante-Nicene Fathers include the Apostolic Fathers: Clement of Rome, Ignatius of Antioch, Polycarp of Smyrna, Barnabas, Justin Martyr, Clement of Alexandria, Origen, Tertullian, and Cyprian. Among the post-Nicene Fathers are Cyril of Alexandria, Athanasius, John Chrysostom, Eusebius of Caesarea, Basil the Great, Ambrose of Milan, Augustine, Pope Leo I, Boethius, Jerome, Gregory of Tours, Pope Gregory the Great, and Bede.