1472 Ivan conquers Perm. Marries the Byzantine princess Sophia, niece of the last emperor of Constantinople, Constantine Palæologus. Assumes the title of czar and adopts the two-headed eagle as the symbol of his authority. In consequence of this marriage many Greeks come to Moscow, bringing with them Byzantine culture.
1474 The princes of Rostov sell their domain to Moscow.
1478 The republic of Novgorod is annexed. The principal citizens are brought prisoners to Moscow, their property is confiscated, the possessions of the clergy serve to endow the boyar followers of Ivan. Ahmed, khan of the Golden Horde, sends ambassadors demanding homage. Ivan puts the envoys to death, except one, who was to take back the news to his master. The reply of Ahmed to this outrage is a declaration of war.
1479 Ivan issues Sudebnik, or Books of Laws, second Russian code after the Russkaia Pravda of Iaroslav. A comparison of two codes shows how much the Russian character was lowered by Mongol domination; it is in the reign of Ivan that we first hear of the use of the knout.
1480 The Mongols invade Russia. The two armies meet on the banks of the Oka and flee from each other in mutual fear. On his retreat Ahmed is killed and his army is annihilated by the Nogai Tatars.
1482 Cannon is used for first time at the siege of Fellin in Livonia. It was founded by the architect and engineer Aristotle Fioraventi of Bologna, the builder of the Kremlin.
1485 The principality of Tver is annexed to Moscow.
1485 The last prince of Vereya leaves his domains by will to Ivan.
1489 Viatka, a daughter of the city of Novgorod and Pskov, and like them a republic, is annexed.
1489 Poppel comes to Moscow as the first German ambassador.