Kaidu–Kublai war

The Kaidu–Kublai war was a war between Kaidu, the leader of the House of Ögedei and the de facto khan of the Chagatai Khanate in Central Asia, and Kublai Khan, the founder of the Yuan dynasty in China and his successor Temür Khan that lasted a few decades from 1268 to 1301. It followed the Toluid Civil War (1260-1264) and resulted in the permanent division of the Mongol Empire. By the time of Kublai's death in 1294, the Mongol Empire had fractured into four separate khanates or empires: the Golden Horde khanate in the northwest, the Chagatai Khanate in the middle, the Ilkhanate in the southwest, and the Yuan dynasty in the east based in modern-day Beijing. Although Temür Khan later made peace with the three western khanates in 1304 after Kaidu's death, the four khanates continued their own separate development and fell at different times.

History
After the Toluid Civil War, Kublai Khan summoned Kaidu at his court, but Kaidu avoided appearing at his court, and his enmity was a constant obstacle to Kublai's ambitions to control the whole Mongol Empire. Baraq was dispatched to Central Asia to take the throne of Chagatai Khanate in 1266, and almost immediately, he repudiated the authority of Kublai as Great Khan. Kaidu and Baraq fought for a while, and Kaidu gained control of the region around Bukhara. Kaidu convinced Baraq to attack the Persia-based Ilkhanate, which was an ally of Kublai Khan's Yuan dynasty based in China. A peace treaty was made among Mengu-Timur, khan of the Golden Horde, Kaidu and Baraq against the Yuan dynasty and the Ilkhanate in around 1267. However, Baraq suffered a large defeat at Herat on July 22, 1270 against Ilkan Abagha. Baraq died en route to meet Kaidu who had been waiting for his weakness. The Chagatayid princes including Mubarak Shah submitted to Kaidu and proclaimed him as their overlord. Sons of Baraq rebelled against Kaidu but they were defeated. Many of the Chagatayid princes fled to the Ilkhanate. Kaidu's early attempt to rule the Chagatayids faced a serious resistance. The Mongol princes such as Negübei, whom he appointed khan of the House of Chagatai revolted several times. Stable control came when Duwa was made khan who became his number two in 1282. The Golden Horde based in Russia also became an ally of Kaidu.

In 1275 Kaidu invaded Ürümqi and demanded its submission, but the Buddhist Idiqut resisted. Kublai sent a relief force to expel him. Kublai's son Nomukhan and generals occupied Almaliq from 1266–76, to prevent Kaidu's invasion. In 1277, a group of Genghisid princes under Möngke's son Shiregi rebelled, kidnapping Kublai's two sons and his general Antong. The rebels handed Antong to Kaidu and the princes to Möngke-Temür. The Great Khan's armies drove Shiregi's forces west of the Altai Mountains and strengthened the Yuan garrisons in Mongolia and Xinjiang. However, Kaidu took control over Almaliq.

Kaidu had waged almost continuous warfare for more than 30 years against Kublai and his successor Temür, though he eventually fell in 1301, when he was defeated and wounded during a battle near Karakorum and died shortly afterwards. The Kaidu–Kublai war had effectively deepened the fragmentation of the Mongol Empire.