In early spring of 1302, Michael IX made his first campaign against the Ottoman Empire to get a chance to prove himself in battle. Under his command, up to 16,000 soldiers were collected, 10,000 of whom were a detachment of mercenary Alans; the latter, however, performed their duty badly and plundered both the Turkish population and the Greek with equal zeal. The Turks chose the moment and descended from the mountains. Michael IX ordered to prepare for battle, but no one listened to him.

After defeat and a short stay in the fortress of Magnesia, Michael IX retreated to Pergamum and then went to Adramyttium, where he met the New Year of 1303, and by the summer he was in the city of Cyzicus. He still didn't give up his attempts to gather a new army to replace the disintegrated old one and to improve the situation. But by that time the Turks had already seized the area along the lower reaches of the (Sangarius) Sakarya River and defeated another Greek army in the town of Bapheus, near Nicomedia (27 July 1302). It was becoming clear to everyone that the Byzantines had lost the war.