The 254 mm 45 caliber Pattern 1891 was a Russian naval gun developed in the years before the Russo-Japanese War that armed coastal defense ships and pre-dreadnought battleships during the Russo-Japanese War and World War I. Guns salvaged from scrapped ships found a second life as coastal artillery. It is believed none were in service during World War II.

Admiral Seniavin, was a Admiral Ushakov-class coastal defense ship built for Imperial Russian Navy during the 1890s. She was one of eight Russian pre-dreadnought battleships captured by the Imperial Japanese Navy from the Russians during the Russo-Japanese War of 1904–1905. She subsequently served in the Japanese Navy under the name Mishima (見島) until sunk as a target in 1936.