In AD 367, Athanasius of Alexanria authored the 39th Festal Letter, or Easter letter. In it, he listed the same 27 books of the New Testament that are in use today. The same letter defines a 22-book Old Testament. The epistle to the Hebrews is missing from some later lists, but the canon defined dogmatically at the Council of Trent matches Athanasius's list and includes the epistle.