Nayan was a prince of the Borjigin royal family of the Mongol Empire. He raised a noteworthy and serious rebellion against the Mongolian Khagan, Kublai Khan. He was a Nestorian Christian. Much of what is known of Nayan was recorded by the Venetian traveller Marco Polo.

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.