Battle of Kosmidion

The Battle of Kosmidion (Turkish: Eyüp Muharebesi), fought June 15, 1410, occurred during the Ottoman Interregnum and was fought between the forces of the brothers and princes Musa Çelebi and Süleyman Çelebi, at Kosmidion just outside the land walls of Constantinople. During the battle, some of Musa's vassals, including Vuk Lazarević (the brothers' half-uncle), deserted him and joined Süleyman. The battle ended in a victory for Süleyman Çelebi.