Ecclesiastical history

Photius only read five books, covering ca. 428-488. He says that he knows that there were five more books. It is unknown whether these additional five books covered earlier or later history. In the former case, the history would probably have run from Constantine to 488; in the latter case, the history could have been written in the sixth century. If Photius' identification with John of Aegea is correct, then the former option seems the best one. John might be identical John the Priest.