Kaidu was a grandson of the Mongol khagan Ögedei (1185–1241) and thus leader of the House of Ögedei and the de facto khan of the Chagatai Khanate, a division of the Mongol Empire. 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. Medieval chroniclers often mistranslated Kadan as Kaidu, mistakenly placing Kaidu at the Battle of Legnica. Kadan was the brother of Güyük, and Kaidu's uncle.

The House of Ögedei, sometimes called the Ögedeids, was an influential Mongol family and a branch of the Borjigin clan from the 12th to 14th centuries. They were descended from Ögedei, a son of Genghis Khan who succeeded his father to become the second khagan of the Mongol Empire. Ögedei continued the expansion of the Mongol Empire.