Patristics or patrology is the study of the early Christian writers who are designated Church Fathers. The names derive from the combined forms of Latin pater and Greek patḗr (father). The period is generally considered to run from the end of New Testament times or end of the Apostolic Age (c. AD 100) to either AD 451 (the date of the Council of Chalcedon) or to the Second Council of Nicaea in 787.