Input (grade 13): The Grand Duchy of Moscow gradually reunified the surrounding Russian principalities, achieved independence from the Golden Horde, and came to dominate the cultural and political legacy of Kievan Rus'.
Output (grade 6): The most powerful successor state to Kievan Rus' was the Grand Duchy of Moscow. This area served as the main force in later Russian unification and the fight against the Golden Horde from Asia.