Mahmudiye, named for Sultan Mahmud II, was the fourth of four Osmaniye-class ironclad warships built for the Ottoman Navy in the 1860s. She was the only member of her class built at the Thames Iron Works, with work lasting from her keel laying in 1863 and her launching in 1864. A broadside ironclad, Mahmudiye carried a battery of fourteen 203 mm (8 in) RML Armstrong guns and ten 36-pounder Armstrongs in a traditional broadside arrangement, with a single 229 mm (9 in) RML as a chase gun. Among the more powerful of Ottoman ironclads, the Navy decided to keep the ship safely in the Mediterranean Sea during the Russo-Turkish War of 1877–1878 to preserve the vessel. She spent the 1880s out of service, though she was heavily rebuilt in the early 1890s and converted into a more modern barbette s