Thou hast destroyed thy soul for the sake of thy body ...

and hast waxed wroth not against a man, but against God." Kurbsky's letters reveal in him a far more cultivated man, with more sense of decency and self control, and even elegance of diction, than the Tzar.

He even reproaches the latter, in one letter, for his ignorance of the proper way to write, and for his lack of culture, and tells him he ought to be ashamed of himself, comparing the Tzar's literary style with "the ravings of women," and accusing him of writing "barbarously." In addition to these letters, Kurbsky wrote a remarkable history of Ivan the Terrible's reign, entitled, "A History of the Grand Principality of Moscow, Concerning the Deeds Which We Have Heard from Trustworthy Men, and Have also Beheld with Our Own Eyes." It is brought down to the year 1578.

This history is important as the first work in Russian literature in which a completely successful attempt was made to write a fluent historical narrative (instead of setting forth facts in the style of the Chronicles), and link facts to preceding facts in logical sequence, deducing effects from causes.
To the reign of Ivan the Terrible belong, also, "A History of the Kingdom of Kazan," by Priest Ioann Glazatly; and the "Memoirs of Alexei Adasheff"-- the most ancient memoirs in the Russian language.
In the mean time, during this same sixteenth century, a new culture was springing up in southwestern Russia, and in western Russia, then under the rule of Poland, and under the influence of the Jesuits.

Many Russians had joined the Roman Church, or the "Union" (1596), by which numerous eastern orthodox along the western frontier acknowledged the supremacy of the Pope of Rome, on condition of being allowed to retain their own rites and vernacular in the church services.