The Battle of Imbros was a naval action that took place during the First World War. The battle occurred on 20 January 1918 when an Ottoman squadron engaged a flotilla of the British Royal Navy off the island of Imbros in the Aegean Sea. A lack of heavy Allied warships in the area allowed the Ottoman battlecruiser Yavûz Sultân Selîm and light cruiser Midilli to sortie into the Mediterranean and attack the Royal Navy monitors and destroyers at Imbros before assaulting the naval base at Mudros.