The Apostolic Age of the history of Christianity is traditionally the period of the Twelve Apostles, dating from the Crucifixion of Jesus (c. 26–36) and the Great Commission until the death of John the Apostle (c. 100). Since it is believed that John lived so long and was the last of the twelve to die, there is some overlap between the "Apostolic Age" and the first Apostolic Fathers, whose writings are used to mark the beginning of the Ante-Nicene Period. It holds special significance in Christian tradition as the age of the direct apostles of Jesus Christ. The major primary source for the "Apostolic Age" is the Acts of the Apostles, but its historical accuracy is questioned by some.