Most of the Ottoman ironclads saw action during the Russo-Turkish War of 1877–1878, with the exception of the four Osmaniyes, which the Ottoman command considered too large and too valuable to risk. The rest of the ships served in the Black Sea, where they supported Ottoman forces in the Caucasus and in the eastern Balkans. One vessel, Lüft-ü Celil, was sunk by Russian artillery while patrolling the Danube. The Ottoman fleet was laid up from the end of the war until 1897, when the government attempted to mobilize the ships during the Greco-Turkish War. After two decades of neglect, most of the ships were found to be unseaworthy, and those vessels that could put to sea were manned by untrained crews who could not effectively operate them. The navy embarked on a major reconstruction program aimed at modernizing the ironclads over the following decade, and many of the vessels were rebuilt or broken up.
Despite having been recently modernized, the Ottoman fleet was in no condition to challenge the powerful Italian fleet during the Italo-Turkish War of 1911–1912, and the bulk of the Ottoman fleet remained in port. Italian cruisers sank one rebuilt ironclad, Avnillah, in the Battle of Beirut. In the First Balkan War, which broke out before the war with Italy ended, a Greek torpedo boat sank Feth-i Bülend in Salonika. In 1913, Asar-i Tevfik ran aground off the coast of Bulgaria; wave action coupled with Bulgarian artillery fire destroyed the ship. Mesudiye took part in two major naval actions against the Greek fleet, the Battle of Elli in December 1912 and the Battle of Lemnos in January 1913, both of which were Ottoman defeats. By the outbreak of World War I in 1914, only Mesudiye served in an active capacity; the other surviving vessels had been reduced to secondary roles like training ships and floating barracks. In December 1914, Mesudiye was sunk by a British submarine in the Dardanelles. After the chaos of the Greco-Turkish War of 1919–1922 subsided, the fleet discarded the ironclads remaining in inventory. The last vessel, Muin-i Zafer, which had been converted into a depot ship for submarines, was scrapped in 1932.
The Osmaniye class was the first group of ironclads ordered by the Ottoman government, part of a naval construction program to replace the heavy losses sustained during the Crimean War of 1853–1856. The contracts were placed with British and French shipyards, with the four Osmaniye-class ships being ordered from Britain. They were broadside ironclads, mounting their battery of guns in traditional gun decks along the sides of the hull, which was typical for the first generation of ironclads built in the early 1860s. They were the largest ironclads of the Ottoman fleet until Mesudiye was completed a decade later in 1875. As the largest and most valuable members of the Ottoman fleet, the Osmaniye class was kept safely in the Mediterranean Sea during the Russo-Turkish War of 1877–1878, because the Ottoman command did not want to risk them in coastal operations in the Black Sea.
The four ships were reduced to reserve status in Constantinople after the war, with the rest of the Ottoman fleet. The four ships were heavily rebuilt in the early 1890s, being converted into more modern barbette ships. Nevertheless, they were in poor condition by the outbreak of the Greco-Turkish War in February 1897, with many of their guns damaged or incomplete. Training exercises conducted in May highlighted the very low standard of training of their crews, and reinforced the decision not to confront the Greek Navy at sea. All four ships were disarmed after the war and laid up, before being decommissioned in 1909. Aziziye, Orhaniye, and Mahmudiye were briefly used as barracks ships; the latter two were sold for scrap in 1913, and Aziziye and Osmaniye followed them to the ship breakers in 1923.