The Grand Duchy of Moscow was a significant state in Eastern Europe from the late 13th century until the 16th century. It emerged as a powerful principality after the decline of the Kievan Rus' and played a crucial role in unifying various Russian territories. The Grand Duchy expanded its influence through military conquests and strategic marriages, eventually laying the groundwork for the future Tsardom of Russia. Under the leadership of notable rulers like Ivan III (Ivan the Great), the Grand Duchy consolidated power and resisted Mongol domination. By the late 15th century, it had become the dominant force in the region, setting the stage for the rise of a centralized Russian state.