During the reign of Ivan the Terrible, secular literature and authors from the highest classes of society again made their appearance; in fact, they had never wholly disappeared during the interval. Ivan the Terrible himself headed the list, and Prince Andrei Mikhailovitch Kurbsky was almost his equal in rank, and more than his equal in importance from a literary point of view. Ivan the Terrible's writings show the influence of his epoch, his oppressed and agitated childhood, his defective education; and like his character, they are the perfectly legitimate expression of all that had taken place in the kingdom of Moscow. The most striking characteristic of Ivan's writings is his malicious, biting irony, concealed beneath an external aspect of calmness; and it is most noticeable in his principal works, his "Correspondence with Prince Kurbsky," and his "Epistle to Kozma, Abbot of the Kirillo-Byelozersk Monastery." They display him as a very well-read man, intimately acquainted with the Scriptures, and the translations from the Fathers of the Church, and the Russian Chronicles, as well as with general history. Abbot Kozma had complained to the Tzar concerning the conduct of certain great nobles who had become inmates of his monastery, some voluntarily, others by compulsion, as exiles from court, and who were exerting a pernicious influence over the monks. Ivan seized the opportunity thus presented to him, to pour out all the gall of his irony on the monks, who had forsaken the lofty, spiritual traditions of the great holy men of Russia.