The culture of ancient Rus' can be divided into different historical periods of the Middle Ages. During the Kievan period (989–), the principalities of Kievan Rus’ came under the sphere of influence of the Byzantine Empire, one of the most advanced cultures of the time, and adopted Christianity. In the Suzdalian period, the Russian principalities gained a wide range of opportunities for developing their political and cultural ties not only with Byzantium, but with the European countries as well, with a resulting impact on architecture and other cultural indicators. By the Muscovite period in the thirteenth century, Russian culture was recovering from the invasion of Batu Khan and subsequent domination of Russian lands by the Golden Horde. The city-states of Novgorod and Pskov, which had been spared the Tatar raids, created an original kind of culture under some influence from their western Baltic neighbors. Finally, only by the end of the fifteenth century, Russia ended its subordination to the Golden Horde with the Great standing on the Ugra river of 1480, which marked the birth of the sovereign Russian state, headed by the Grand Prince of Moscow. Kievan period This new cultural era dates back to the adoption of Christianity in 989, when the principalities of Kievan Rus’ came under the sphere of influence of the Byzantine Empire, one of the most advanced cultures of the time. Vladimir the Great's political choice determined the subsequent development of the Rus culture. Byzantine masters built their first cathedrals in Rus’ and decorated their interiors with mosaics and murals. Samples of pictorial art, such as icons and miniatures of illuminated manuscripts, came to Kiev and other cities from Constantinople. After the completion of the most important cathedral of Kievan Rus’—Saint Sophia Cathedral in Kiev, named after the principal cathedral of the Byzantine capital—a Russian clergyman, the metropolitan Ilarion, wrote his work On Law and Grace (Slovo o zakone i blagodati), confirming the basics of Russia's new Christian world outlook. Thus, Kievan Rus’ became part of the broader Christian world, under Byzantium's influence. The metropolitan of Kiev was subordinated to the Patriarch of Constantinople. The Russian principalities adopted the Byzantine culture during a time when the apogee of the Eastern Roman Empire had already been overcome, but its decline was still far ahead. Byzantium remained the only direct successor of the Hellenistic world, which had applied the artistic achievements of antiquity to the spiritual