Alexius, Metropolitan of Moscow was a 14th-century prelate who served as the Metropolitan of Kiev and all Rus' starting in 1354. Born Eleutherius to a boyar family in Moscow, he entered monastic life around 1313. He played a vital political role by acting as regent for the young princes Dmitrii Donskoi and Vladimir the Bold. Throughout his influential career, he navigated complex relations between the Muscovite state, the Golden Horde, and various regional principalities.