The Bayan class was a group of four armored cruisers built for the Imperial Russian Navy around the beginning of the 20th century. Two of the ships were built in France, as Russian shipyards had no spare capacity. The lead ship, Bayan, was built several years earlier than the later three. The ship participated in several of the early naval battles of the Russo-Japanese War of 1904–05, and provided naval gunfire support for the Imperial Russian Army until she struck a mine. Bayan was trapped in harbor during the subsequent Siege of Port Arthur, and was sunk by Japanese artillery. She was salvaged and put into service with the Imperial Japanese Navy with the name of Aso. She mostly served as a training ship before she was converted into a minelayer in 1920. The ship was sunk as a target in 1