The Battle of Pelekanon results in a Byzantine defeat by the Ottoman Empire.
The Battle of Pelekanon, also known by its Latinised form Battle of Pelecanum, occurred on June 10–11, 1329 between an expeditionary force by the Byzantines led by Andronicus III and an Ottoman army led by Orhan I. The Byzantine army was defeated, with no further attempt made at relieving the cities in Anatolia under Ottoman siege.