The Battle of Bapheus occurred on 27 July 1302 between an Ottoman army under Osman I and a Byzantine army under George Mouzalon. The battle ended in a crucial Ottoman victory, cementing the Ottoman state and heralding the final capture of Byzantine Bithynia by the Turks. According to Halil İnalcık, the Ottomans achieved its characteristics and qualities of state after this battle (Bafeus Savaşı) near Yalova.