Dmitry Donskoy was a 14th-century Grand Prince of Moscow and Vladimir who reigned from 1359 until his death in 1389. Born in Moscow, he ascended to power as a child following his father's death and was initially guided by Metropolitan Alexius. He is most famous for being the first Russian ruler to directly confront Mongol authority, achieving a significant military triumph against the forces of Mamai at the Battle of Kulikovo in 1380. This victory, which earned him his nickname, helped consolidate the prestige and authority of the Moscow principality.