08/10/2023
In 1246 Güyük was crowned as Great Khan of the Mongols. His coronation was bitterly opposed by his rival, Batu, Great Khan of the Golden Horde. Their enmity almost led to civil war, and was a heaven-sent opportunity for the Empire of Nicaea to save itself from Mongol invasion.
Güyük undermined Batu by dismissing his commander, Baiju, and interfering in the Seljuk sultanate of Rum, now a Mongol vassal state. The dismissal of Baiju came in the nick of time for the Roman emperor, Vatatzes: according to Matthew Paris, an English chronicler, Baiju had previously sent envoys to Rome, asking the Pope for a military alliance against Nicaea.
Vatatzes was in a dangerous position. He was the only ruler of Anatolia not to have sent an embassy to the Mongol leaders; according to Mongol political theory, any state that rejected their supremacy, and refused diplomatic contact, should be treated as hostile.
The emperor countered Mongol diplomacy by sending his own embassy to Innocent IV, offering to negotiate a union of the Roman and Orthodox churches. In response to Baiju's offer of military alliance with the Pope, Vatatzes renewed his own alliance with the Seljuk sultan, Kaykaus II.
The emperor went even further. In 1248 he negotiated a marriage with Kaykaus: according to Armenian sources, the sultan agreed to become the son-in-law of 'Lascaris', King of the Romans i.e. John Vatatzes. Kaykaus was probably married to one of the emperor's kinswomen, though her name is unrecorded.
This marriage was another counter-move against the Mongols, who had nominated Kaykaus's younger brother, Kilij Arslan IV, as sultan of Rum. So now all the pieces on the board were finely balanced.
