The Grand Duchy of Moscow, Muscovite Russia, Muscovite Rus' or Grand Principality of Moscow was a Rus' principality of the Late Middle Ages centered on Moscow, and the predecessor state of the Tsardom of Russia in the early modern period. It was ruled by the Rurik dynasty, who had ruled Rus' since the foundation of Novgorod in 862. Ivan III the Great titled himself as Grand Prince of all Rus'.
