[2] According to Ibn Bibi and al-Aqsarayi, Kaykaus plotted to overthrow the Emperor Michael VIII, but his plans were revealed by his maternal uncle, Kyr Kedid.
[3] Nicephorus Gregoras is unique in claiming that Kaykaus first made contact with the Bulgarian tsar, Konstantin Tikh, who enlisted his Mongol overlords.
According to Pachymeres, they were an autonomous band, de facto independent of the authority of the Golden Horde.
Michael VIII was forced to release Kaykaus, and signed a treaty with Berke, in which he agreed to give one of his daughters, Euphrosyne Palaiogina, in marriage to Nogai.
Berke's invasion of Thrace may have been the war which delayed Niccolò and Maffeo Polo's journey in the 1260s.