The Battle of Bafias, or the Battle of Koinohisar, was fought on 2 July 1302 on the shores of Yalakova between the Ottoman army under Osman I and the Byzantine army under George Mouzalan. The war ended in a major victory for the Ottoman Empire. As a result, the words of Uthman’s bravery and war tactics in Anatlia and the surrounding lands came to everyone’s mouth. Warriors, Ghazis, Begs scattered in different parts slowly joined the army of Usman.
Source: Wikipedia