Kiev fell under the rule of Varangians (see Askold and Dir, and Oleg of Novgorod) and became the nucleus of the Rus' polity. The date given for Oleg's conquest of the town in the Primary Chronicle is 882, but some historians, such as Omeljan Pritsak and Constantine Zuckerman, dispute this and maintain that Khazar rule continued as late as the 920s (documentary evidence exists to support this assertion � see the Kievian Letter and Schechter Letter.) Other historians suggest that the Magyar tribes ruled the city between 840 and 878, before migrating with some Khazar tribes to Hungary. According to these the building of the fortress of Kiev was finished in 840 by the lead of Ke? (Keve), Cs�k and Ger�b, the three brothers, possibly members of the Tarj�n tribe (the three names are mentioned in the Kiev Chronicle as Kyj, Shchak and Khoriv, none of them are Slavic names and it has been always a hard problem to solve their meaning/origin by Russian historians. Though the three names was put into to the Kiev Chronicle in the 12th century and they were identified as old-Russian mythological heroes).During the 8th and 9th centuries, Kiev was an outpost of the Khazar empire. However, being located on the historical trade route from the Varangians to the Greeks and starting in the late 9th century or early 10th century, Kiev was ruled by the Varangian nobility and became the nucleus of the Rus' polity, whose 'Golden Age' (11th to early 12th centuries) has from the 19th century become referred to as Kievan Rus'. In 968, the nomadic Pechenegs attacked and then besieged the city. In 1203 Kiev was captured and burned by Prince Rurik Rostislavich and his Kipchak allies. In the 1230s the city was besieged and ravaged by different Rus' princes several times. In 1240 the Mongol invasion of Rus led by Batu Khan completely destroyed Kiev, an event that had a profound effect on the future of the city and the East Slavic civilization. At the time of the Mongol destruction, Kiev was reputed
