Третий Рим
Under the reign of Ivan the Great (1462–1505), Moscow became a major regional power, and the annexation of the vast Republic of Novgorod in 1478 laid the foundations for a Russian national state. After the Fall of Constantinople in 1453 the Russian princes started to see themselves as the heirs of the Byzantine Empire. They eventually took on the imperial title of Tsar, and Moscow was described as the Third Rome.