[3][4][5] To counter the threat to Nicomedia, Michael's father, Andronikos II Palaiologos (r. 1282–1328), sent a Byzantine force of some 2,000 men (half of whom were recently hired Alan mercenaries), under the megas hetaireiarches, George Mouzalon, to cross over the Bosporus and relieve the city.

After this battle the countryside of Bithinya was left practically defenseless so Osman used this opportunity to conquer the castle of Koyunhisar and the costal town of Gemlik.

The Byzantine defeat also sparked an exodus of the Christian population from the area into the European parts of the empire, further altering the region's demographic balance.

[8] Coupled with the defeat at Magnesia, which allowed the Turks to reach and establish themselves on the coasts of the Aegean Sea, Bapheus thus heralded the final loss of Asia Minor for Byzantium.

[12] After the victory, thousands of ghazis, who believed that the resistance of the Byzantine Empire had been broken, came in hordes from the interior of Anatolia to Bithynia to raid for spoils.