Ivan III (1440-1505), called Ivan the Great, was grand duke of Moscow from 1462 to 1505. He completed the unification of Russian lands, and his reign marks the beginning of Muscovite Russia.

Born on Jan. 22, 1440, in Moscow, Ivan was the oldest son of Basil II. He was married when he was 12 years old to Princess Maria of Tver. When Basil died in 1462, the 22-year-old Ivan became the grand duke of Moscow without being confirmed by the Mongol Khan. Ivan limited his allegiance to the Golden Horde to the sending of presents instead of regular tribute, finally discontinuing even those. Several Mongol attempts to subjugate the Russians failed, the last one in 1480.

The accomplishment for which Ivan is best known is the consolidation of Muscovite rule. His predecessors had increased Moscow's territory from less than 600 square miles under Ivan II to more than 15,000 square miles at the end of Basil II's...