The Battle of the Yellow Sea (Japanese: 黄海海戦 Kōkai kaisen; Russian: Бой в Жёлтом море) was a major naval engagement of the Russo-Japanese War, fought on 10 August 1904. In the Russian Navy, it was referred to as the Battle of 10 August. The battle foiled an attempt by the Russian fleet at Port Arthur to break out and form up with counterparts from Vladivostok, forcing them to return to port.