The Moscow Principality was a medieval state that emerged in the 13th century in the region of modern-day Russia. It began as a small territory centered around the city of Moscow and gradually expanded its influence through strategic marriages, alliances, and military conquests. The principality played a crucial role in the unification of Russian lands. By the late 15th century, the Moscow Principality had grown powerful enough to challenge the Golden Horde, a Mongol empire that had dominated the region. Under the leadership of Ivan III, also known as Ivan the Great, it laid the foundation for the future Tsardom of Russia.