The name "Apostolic Fathers" was first applied in 1672 to a group of five writers who were taken either to have been in touch directly with some of the original Twelve Apostles or, in the next generation, to reflect the teaching of their immediate successors: Clement of Rome (fourth in the list of Popes), Ignatius (second bishop of Antioch), Polycarp of Smyrna (recorded as a disciple of the evangelst John), "Barnabas" (reputedly St. Paul's co-worker), and a Hermas, associated, though wrongly, with Hermas of Romans 16.14. With the later addition of Papias of Hierapolis and the unknown writer of the Epistle to Diognetus, the number of the Apostolic Fathers rose to seven, a final addition to the group was the Didache, a brief, early manual on morals and Church practice. Anything but homogenous in origin, form, and purpose, and ranging widely in all of these respects, these writings are of prime importance for the understanding of the Church around the year 100 A.D. Unless it be the Apostles' Creed itself, nothing precedes them in the development of Patrology.