The Apostolic Fathers are a small number of Early Christian authors who lived and wrote in the second half of the 1st century and the first half of the 2nd century. They are acknowledged as leaders in the early church, although their writings were not included in the New Testament. They include Clement of Rome, Ignatius of Antioch, Polycarp of Smyrna, the author of the Didache, and the author of the Shepherd of Hermas.