Great stand on the Ugra river

The Great Standoff on the Ugra river (Великое cтояние на реке Угре in Russian, also Угорщина (Ugorschina in English, derived from Ugra) was a standoff between the forces of Akhmat, Khan of the Great Horde, and the Grand Prince Ivan III of Russia in 1480, which resulted in the retreat of the Tatars and is often taken as the end of Tatar rule over Russia.

The battle
On October 8, 1480 Akhmat Khan planned to bypass the Oka river from the west and thus avoid Ivan's regiments which were located in Kolomna, Serpukhov and Tarusa. This would allow Akhmat Khan to unite his army with Casimir's. Akhmat Khan's forces approached the Ugra river. The main Russian defense line ran along the Oka from Nizhny Novgorod to Kaluga where the Oka turns from north to east (the Ugra extends this line to the west from Kaluga toward Lithuania). At the Ugra, Akhmat Khan was met by the Russian army under the joint command of Ivan Molodoy (Ivan Junior, Ivan's son) and Andrey Menshoy (Andrey Smaller One, Ivan's brother). Akhmat's attempt to cross the Ugra river was rebuffed in a 4-day battle. The Muscovite chronicle says the Russians succeeded through the use of firearms, of which the Tatars had none.

The Standoff
After the battle, Akhmat then retreated to the town of Vorotynsk, where he decided to wait for Casimir's army. Ivan III moved his army to Kremenets and started to negotiate with the khan, in an attempt to buy some time to restore his relations with his rebellious brothers (hence, the Great standing on the Ugra river). It took Ivan III four days (from September, 30 to October, 3) to reconcile with his brothers and another 17 days (until 20 October) for his brothers' armies to arrive at Kremenets. Unlike Dmitry Donskoy in a similar situation one hundred years before, Ivan decided not to cross the river, but to keep on his shore and bide his time.

Watching the increasing Russian army and receiving no word from the Polish king, Akhmat chose not to attack the Russians. In the meantime, Casimir IV was dealing with his own country's internal affairs and fighting against Muscovy's ally, Crimean Khan Mengli I Giray, that invaded Poland while king's army was away. Ivan also sent a regiment under command of Prince Vasily Nozdrevaty of Zvenigorod, to encircle Akhmat. Nur Devlet Giray, brother of Mengli Giray, was in this regiment.

Akhmat was probably waiting for the river to freeze so that it could be crossed, and for the arrival of Lithuanian forces. These did not arrive because of Crimean raids and internal troubles in Lithuania. When winter approached, the Tatar army was lacking supplies and was suffering from epidemics and cold weather.

On October 28, Ivan gradually started to pull his armies back to Kremenets for winter quarters. Akhmat waited for reinforcements until November 11 and then turned south. Among other reasons of Akmat's retreat was the possible threat of Crimean, Nogai or other attacks on his unprotected home base, a common problem in nomadic warfare. As Nikolai Karamzin wrote in his "History of Russian State", "It should have been an odd image: two armies ran away from each other, not pursued by anyone".

The Tatar retreat was seen as a victory in Muscovy. Ivan and his armies returned to Moscow to celebrate.

Results
On January 6, 1481 Akhmat Khan was killed in a clash with the Nogais under Ibak Khan, a princeling from the Khanate of Sibir. In 1502 Crimea destroyed the Great Horde as an organization thereby removing the buffer between Russia and Crimea and leading to a series of Russo-Crimean wars that lasted until 1784.

In nationalist history, the Ugra Standoff is taken as the end of the so-called "Tatar Yoke". Modern writers are more skeptical and see it as an important landmark in the gradual expansion of Russia and the gradual decline of the Turko-Mongol empire.

Perhaps the most important result of the Russo-Crimean alliance was its effect on Lithuania. In 1480-1515 Muscovy (Russia) expanded out of its Oka-Volga cradle west to Smolensk and southwest across the Ugra and down the west side of the Oka as far as Novgorod-Seversky.