The Battle of Kulikovo (Russian: Куликовская битва, romanized: Kulikovskaya bitva) was fought between the forces of Mamai, a powerful Mongol military commander of the Golden Horde, and Russian forces led by Grand Prince Dmitry of Moscow. The battle took place on 8 September 1380, at Kulikovo Field near the Don River (now Tula Oblast, Russia) and was won by Dmitry, who became known as Donskoy ("of the Don") after the battle.
Although the victory did not end Mongol domination over Russia, it is traditionally regarded as the turning point at which Mongol influence began to wane and Moscow's power began to rise. The battle would allow Moscow to strengthen its claims of ascendancy over the other Russian principalities, in which it would ultimately become the centre of a centralized Russian state.
The Great Stand on the Ugra River in 1480 would mark another important turning point in this power shift. Even though the successor states of the Mongol Empire would manage to burn Moscow in 1571, the Russians defeated them again at the Battle of Molodi later that year.
Following the Mongol invasion of Rus' in the 13th century, the numerous principalities became vassals of the Golden Horde. During this period, the principality of Moscow was growing in power and was often challenging its neighbours over territory, including clashing with Ryazan. Thus, in 1300, Moscow seized the city of Kolomna from Ryazan, and the prince of Ryazan was killed after several years in captivity.
After the killing of Khan Berdi Beg of the Golden Horde in 1359, the Great Troubles had arisen there. Warlord (temnik) Mamai, who was the son-in-law and beylerbey of Berdi Beg, soon took power in the western part of the Golden Horde. Mamai enthroned Abdullah Khan in 1361 and after his mysterious death in 1370, Muhammad Bolak was enthroned. Mamai was not a Genghisid (descendant of Genghis Khan), and as such his grip on power was tenuous, as there were true Genghisids with claims to mastery. Therefore, he had to constantly fight for supreme power and at the same time struggle against separatism. While there was a war of succession in the declining Golden Horde, new political powers were appearing, such as the Grand Duchy of Lithuania, the Principality of Moscow, and the Principality of Ryazan.
Meanwhile, the Grand Duchy of Lithuania continued its expansion. It competed with Moscow for supremacy over Tver and in 1368–1372 made three campaigns against Moscow. After the death of Algirdas in 1377, his eldest sons Andrei of Polotsk and Dmitri of Bryansk began to struggle with their step-brother Jogaila for their legitimate right to the throne and allied with the Grand Prince of Moscow.
Simultaneously with the beginning of the Great Troubles in the Horde in 1359, Prince of Moscow Ivan II died and the new Khan of the Horde by his jarliq (law pronouncement) transferred the throne of the Grand Duchy of Vladimir to the Prince of Nizhny Novgorod. But the Moscow elites (in 1359, the new Prince Dmitry was only 9 years old) did not accept this. They used equally armed force and bribes to various Khans and as a result, in 1365, forced the princes of Nizhny Novgorod to finally give up claims to the Grand Duchy of Vladimir. In 1368, the conflict between Moscow and Tver began. Prince of Tver Mikhail used the help of Lithuania, and in addition, in 1371 Mamai gave him a jarliq to the Grand Duchy of Vladimir. But the Moscow troops simply did not let the new "Grand Prince" enter Vladimir, despite the presence of the Tatar ambassador. The campaigns of the Lithuanian army also failed and so the jarliq returned to Dmitry. According to the results of the truce with Lithuania in 1372, the Grand Duchy of Vladimir was now recognized as the hereditary possession of the Moscow princes. In 1375 the Prince of Tver once again received a jarliq for the Grand Duchy from Mamai. Then Dmitri with a strong army (larger than it was in the Kulikovo battle) quickly moved to Tver and forced it to capitulate. Mikhail recognized himself as the "little brother" of the prince of Moscow and ensured to participate in wars with the Tatars.
Open conflict between Dmitry and Mamai began in 1374, though the exact causes are unknown. It is believed that the illegitimacy of the Mamai's puppet khans was by that time too obvious; he also demanded more and more money as he lost the war for the throne of the Golden Horde. In the following years the Tatars raided Dmitry's allies and the Moscow troops made a campaign against Tatars over the Oka River in 1376 and seized the city Bolghar in 1377. In the same year "Mamai's tatars" defeated the army of Nizhny Novgorod with an auxiliary detachment left by Dmitry at the Battle on Pyana River. The Tatars then began to raid Nizhniy Novgorod and Ryazan.
Mamai continued his attempts to reaffirm control over the tributary lands of the Golden Horde. In 1378, he sent forces led by the warlord Murza Begich to ensure Prince Dmitri's obedience, but this army suffered a defeat at the Battle of the Vozha River. Meanwhile, another khan, Tokhtamysh, seized power in the eastern part of the Golden Horde. He enjoyed the support of Tamerlane and was ready to unite the entire Horde under his rule. In 1380, despite the threat from Tokhtamysh, Mamai chose to personally lead his army against the forces of Moscow. In preparation for the invasion, he allied with Prince Jogaila of Lithuania. Ryazan Prince Oleg was defeated by Mamai in 1378 (and his capital was burnt), he had no strength to resist Mamai, and Ryazan's relationship with Moscow had long been hostile. Therefore, in the campaign of 1380 Oleg took the side of Mamai, although this fact is sometimes challenged. Mamai camped his army on the bank of the Don River, waiting for the arrival of his allies.
In August 1380 Prince Dmitri learned of the approaching army of Mamai. It is alleged that Oleg Ryazansky sent a message to him. The interpretations of such an act are varied: some believe that he did this because he was not a supporter of Mamai, while others believe that he expected to intimidate Dmitry – in the past, none of the Russian princes dared to meet in battle with the Khan himself. Nevertheless, Dmitry quickly assembled an army in Kolomna. There he was visited by the ambassadors of Mamai. They demanded an increased tribute, "as under the Khan Jani Beg". Dmitry agreed to pay tribute, but only in the amount provided for by his previous contract with Mamai. In Kolomna, Dmitry received updated information about the Mamai itinerary and about the approaching forces of Jogaila. So, after reviewing the army, on August 20 he moved west along the Oka River, crossed it at the town of Lopasnya on August 24–25 and moved south towards Mamai. On September 6, the Russian army reached the Don River, where it was reorganized, taking into account the units that joined during the movement from Kolomna. At the council, it was decided to cross the Don before the enemies could combine their forces, although this step cut off the path to retreat in case of defeat.
The earliest chronicle tales do not provide details on the composition of the Russian army. Among the dead in the battle there are named only Princes of Beloozero (which by that time were in strong submission to Moscow), noble Moscow boyars, and Alexander Peresvet. The latter, according to some sources, was from Lithuania (rather from Bryansk). The poetic story "Zadonshchina", along with a figure of 253,000 fallen in the battle, gives dozens of dead princes, boyars, "Lithuanian pans" and "Novgorod posadniks" from all over North-Eastern Rus', but all this data is doubtful. There are mentioned even 70 fallen Ryazan boyars, although according to all other sources the Duchy of Ryazan was the forced ally of Tatars. According to the Russian historian Gorskii, the list of princes and commanders (according to which one can estimate the composition of the army), cited in "The Tale of the Rout of Mamai" and the sources derived from it, is completely untrustworthy. However, he identified two chronicles with a sufficiently high level of reliability. According to his reconstruction, detachments from most of North-Eastern Russia, part of the Princes of the Smolensk Land and part of the Upper Oka Principalities were represented in the army of Dmitry, but there were no troops from Nizhny Novgorod and from the Principality of Tver (except for Kashin, who became independent under the treaty of 1375). The probability of the presence of a detachment from Veliky Novgorod is quite high (although in the early Novgorod chronicles, such information is not available). Grand Duchy of Ryazan could be represented by the troops of the appanage Principality of Pronsk, whose rulers have long rivalled their Grand Princes. Also, the presence of small detachments from the borderlands of Murom, Yelets and Meshchera is "not excluded". Probably, the army of Dmitri was enforced by Jogaila's rebellious brothers Andrei of Polotsk and Dmitri of Bryansk.