The historical nucleus of Russia. Kiev, now in Ukraine, was probably founded in the 6th or 7th century, the centre of a feudal state ruled by the Rurik dynasty from the 9th to the 13th century. About 878 Igor advanced along the Dnieper River from Novgorod and made Kiev capital of the Varangarian–Russian principality. As the oldest established city it is known as ‘the mother of Russian cities’ and also ‘the Jerusalem of Russia’ as the first centre of the Greek Orthodox Church in Russia.