The Ostromir Gospel, a masterpiece of the book art of Kievan Rus’, is an item of exceptional magnificence. It is the oldest East Slavic manuscript dated by its colophon, which also bears the name of a copyist. According to the Greek reckoning of biblical chronology, it was executed in 6564–6565 after Creation, i.e., in 1056–1057; it marks the first burgeoning of the early Christian state of Rus’ and the weight of the Byzantine inheritance in the genesis of its art. It was commissioned by Posadnik (governor) Ostromir (Prince Iziaslav’s powerful representative in Novgorod), whose influence extended throughout northwestern Rus’. The luxurious book he had copied and painted was intended for the recently built cathedral of St. Sophia in Novgorod, which must have given the manuscript the privileged status of a state emblem.“
From the page of the Louvre for the exhibition Holy Russia.