"Mesudiye" became the flagship of the Ottoman naval forces in the Black Sea during the Russo-Turkish War, but she saw no action. Like the rest of the fleet, she was in poor condition by the outbreak of the Greco-Turkish War, and she was accordingly modernized in the aftermath. Gio. Ansaldo &amp; C. rebuilt the vessel into a pre-dreadnought type vessel, though she never received her intended new main battery of two guns. During the Italo-Turkish War, she remained inactive with the rest of the fleet, safely behind the fortifications of the Dardanelles, but she saw action during the First Balkan War at the battles of Elli and Lemnos. During the latter engagement, damage sustained forced her to retreat. She continued on in service during World War I, acting as a guard ship to protect the minefields laid to block the entrances to the Dardanelles, and it was in this role that she was torpedoed and sunk by the British submarine on 13 December 1914.