He ruled parts of modern-day Xinjiang and Central Asia during the 13th century, and actively opposed his uncle, Kublai, who established the Yuan dynasty.

[6] In 1260, Marco Polo described Yarkand, part of the area under Kaidu as "five days' journey in extent"; that its inhabitants were mostly Muslim although there were also some Nestorian and Jacobite Assyrians; and that it had plenty of food and other necessities, "especially cotton.

"[7] Nevertheless, despite benefiting from the favor of Möngke, Kaidu arrested the khan's envoy, the judge Shi Tianlin, in 1256, and held him prisoner for twenty years.

Neither side gained control of the cities; the administration of these instead devolved to Mas'ud Beg, while Baraq and Kaidu agreed to reside only in the deserts and mountains.

[13] The Chagatayid princes, including Alghu's sons and Baraq's predecessor Mubarak Shah, submitted to Kaidu, who was invested as ruler of the previously dispersed Ulus of Ögedei at a kurultai at Talas in August/September 1271.

The new khan was no threat to Kaidu, in part because of his physical feebleness, but that also meant that he could not ensure stability in the Ulus by curtailing the attacks of the rebels.

The successes of Kublai's general An Tong gave Kaidu pause (or at least he pretended to consider the great khan's demands), but in the end he refused to submit.

However, in 1276 a group of princes rebelled, seeking to make Möngke's son Shiregi great khan, and captured Nomukhan, his brother Kököchü, and their general An Tong.

Having solidified his position in the west, he was also able to recover control over Almaliq in the east, and further enhanced his military capabilities by the absorption of the forces of the rebel princes who surrendered to him.

[16] [17] For his part, Kublai struck back with economic reprisals and ensconced his forces at Beshbaliq from 1278, and proceeded to establish a chain of postal stations and military colonies in Uighuria and along the edge of the Tarim Basin.

After varied success, Kaidu and Duwa were able to take over Beshbaliq in 1286, forcing Kublai's troops to evacuate Uighuria and the Tarim Basin over the following years.

[18] When Nayan rebelled against Kublai in Manchuria in 1287 as head of a coalition of the descendants of Chinggis Khan's brothers, he sought Kaidu's support.

Kublai's commander Bayan was now stationed in the region, with the aim of expelling any remaining forces of Kaidu's and repulsing future attacks.

His retreat, however, was quickly followed by reverses at the hands of Kublai's commanders, especially Bayan (who defeated Ariq Böke's son Melik Temür in 1292) and Tuq Tuqa (who carried operations west of the Altai mountains and captured three thousand of Kaidu's men in 1293).

[21] After considering a potential coalition against Kaidu and Duwa with the Ilkhan and Bayan of Eastern Qipchaq, the great khan Temür left operations against them to his brother Kammala and nephew Qayishan.

Although badly outnumbered and still delaying in the hope of receiving aid from Duwa, Kaidu was forced to make his stand south of the Altai Range, at Mount Tiejiangu, on 3 September, 1301.

Here, Kaidu was wounded and suffered a serious defeat; only a ruse, lighting numerous camp fires during the night following the battle saved him from pursuit, as the enemy assumed he had received large reinforcements.

[22] Sometimes considered to have aimed at nothing less than the position of great khan, Kaidu seems to have been concerned with reestablishing the Ulus of Ögedei and asserting its control over that of Chagatai.

He had asserted his domination over the Ulus of Chagatai by force, and only found significant cooperation, which lasted for two decades, once he installed Duwa as khan in 1282.

[25] The Jochid rulers of Qipchaq, the so-called Golden Horde, Berke and Möngke Temür, were instrumental in Kaidu's rise to power.

Although he remained basically friendly, Möngke Temür later exhibited a degree of cooperation to the great khan, effectively adopting a neutral stance; his cousins Qonichi and Bayan, rulers of the eastern wing of the Golden Horde, on the other hand, were Kaidu's neighbors along the Jaxartes, and quickly became his rivals over territory and revenue.