Ivan III (or Ivan the Great) was the son of Grand Prince
Vasily II of Russia. He came to the throne on his father's death in
1462, though he had been working with his blind father for several years. Ivan's major achievement was to change Russia from a group of cities ruled by princes only partly under the control of one Grand Prince, to a country under one ruler. He made
Russia essentially equivalent to
Muscovy, the lands ruled by the Prince of Moscow (and indeed the country was called Muscovy in many European languages until the early 1700s.) He also formalized the freedom of Russia from the Mongols who had first conquered it around
1240.
Ivan's ancestors had already much increased the size of Moscow's lands from about 600 square miles at the time of Ivan I to about 15,000 when Ivan III took office. But by purchase, conquest, or inheritance, Ivan acquired much more. Most famously, he conquered the semi-independent cities of Novgorod and Tver, who had turned to Lithuania as a source of military support, and deported their leading families to other parts of Russia. In 1493 Ivan adopted the title of "Sovereign of All Russia," and made it clear that he felt all areas formerly Russian in the period of rule from Kiev should become Russian again. Much of this land was Lithuanian- or Polish-controlled, and several times Ivan went to war and gained land in the southwest.
Ivan became Grand Prince without being confirmed by the Khan of the Mongols, and only irregularly sent them "gifts" instead of the regular tribute they had received in earlier times. In 1480, Ivan declared that Russia was no longer a vassal of the Khan, and Mongol troops were sent in, allied with King Casimir, who ruled both Poland and Lithuania. Ivan got the support of one of the rival Khans, Mengli-Geray, who had broken off from the main Mongol government. Mengli-Geray raided Poland-Lithuania and kept their troops from marching into Russia, while the Russian troops sent an attack to the Mongol capital of Sarai. On finding out their home base was threatened, the Mongol troops retreated from their incursion into Russia, and shortly thereafter their Khan was killed. After this, the authority of the Mongols in Russia was gone.
In 1472, Ivan married a Byzantine princess, Sophia. Constantinople had already been conquered by the Ottoman Turks, and this marriage was used as a symbol of Moscow becoming the successor of Constantinople as a religious and cultural center. Ivan added the Byanzantine two-headed eagle to his coat of arms, and the Russian Orthodox Church leaders considered Moscow to be the Third Rome, the center of Christanity to follow Rome and Constantinople. Ivan made much more contact with the rest of Europe than Russians had done in a long time, and made several diplomatic alliances, but kept his independence. The Holy Roman Emperor offered him a crown as King rather than Grand Prince, he refused to let someone else appoint him as ruler of his own land, and himself took the title of "Tsar" (derived from "Caesar" and therefore higher than just "king"). Western suggestions for the reuniting of the Roman Catholic Church and the Orthodox Church were also turned down.
In 1497 Ivan had the laws of Moscow written down in one place for the first time. He also restricted the rights of serfs, allowing them to change the location they lived in only once a year on a certain feast day. Around this time, he also had some fights with his wife and son Vasily, so that he almost proclaimed his grandson Dmitry as heir, but after about a year he was reconciled with Sophia and left Vasily as the successor. Ivan died in 1505 and Vasily III became Tsar.