Christian historiography began early, perhaps as early as Luke-Acts, which is the primary source for the Apostolic Age. Writing history was popular among Christian monks and clergy in the Middle Ages. They wrote about the history of Jesus Christ, that of the Church and that of their patrons, the dynastic history of the local rulers. In the Early Middle Ages historical writing often took the form of annals or chronicles recording events year by year, but this style tended to hamper the analysis of events and causes. An example of this type of writing is the Anglo-Saxon Chronicles, which were the work of several different writers: it was started during the reign of Alfred the Great in the late 9th century, but one copy was still being updated in 1154.