The Bayan was the name ship of the four Bayan-class armoured cruisers built for the Imperial Russian Navy in the first decade of the 20th century. The ship had to be built in France because there was no available capacity in Russia. Bayan was assigned to the First Pacific Squadron after completion and based at Port Arthur from the end of 1903. She suffered minor damage during the Battle of Port Arthur at the beginning of the Russo-Japanese War of 1904–05 and supported destroyers as they patrolled outside the harbour. After bombarding Japanese positions in July 1904, the ship struck a mine and was out of action for the next several months. Bayan was sunk during the Siege of Port Arthur and was then salvaged by the Japanese after the war.

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 1932.