Epistolography, or the art of writing letters, is a genre of Byzantine literature similar to rhetoric that was popular with the intellectual elite of the Byzantine age. The letter became a popular literary form in the fourth century AD and combined Christian and classical Greek traditions. The collections of the emperors Julian, Libanios, and Synesius, and the work of the Cappadocian Fathers were particularly notable, while letters of Aristotle, Plato and the Pauline Epistles of the New Testament were influential in the development of the genre.