In 1203–1205, he had wandered across Greece, seeking the support of powerful local grandees, before being captured by Boniface of Montferrat and held captive until ransomed by his first cousin, Michael of Epirus, in 1210.

Kaykhusraw, having found in supporting Alexios's cause a perfect pretext for attacking Nicaean territory, sent an emissary to Theodore at Nicaea, calling upon him to relinquish his domains to the legitimate emperor.

[11][12] Kaykhusraw's army, with Alexios III in tow, laid siege to Antioch on the Maeander, which he hoped to use as a base to subdue the rest of the Meander Valley.

Nevertheless, it was clearly a considerably larger force than the army Theodore managed to scrape together: both Gregoras and Akropolites put it at 2,000 men (3,000 according to George of Pelagonia), of whom 800 were Latin[n 1] and the rest Byzantine Greeks.

[13][16] According to Gregoras, Laskaris intended to catch the Turks off guard by his rapid approach, but Akropolites relates that the Nicaean ruler sent Kaykhusraw's ambassador, whom he had taken along, to inform his master of his arrival.

[18][19] As the sources narrate, at this moment of victory, the Seljuk sultan sought out Laskaris, who was hard pressed by the attacking Turkish troops.

Kaykhusraw charged his enemy and gave him a heavy blow on the head with a mace, so that the Nicaean emperor, dizzied, fell from his horse.

The battle ended the Seljuk threat: Kaykhusraw's son and successor, Kaykaus I, concluded a truce with Nicaea on 14 June 1211, and the border between the two states would remain virtually unchallenged until the 1260s.

[24] The victory at Antioch on the Meander gave Laskaris considerable prestige, and the capture of Alexios ended internal opposition to his rule.

However, even though the Nicaean Empire would strengthen (at the cost of the Latins) and the Seljuks would weaken, the Turks, under Ottoman leadership, would ultimately conquer Byzantine Asia Minor a little over 100 years later.