Port Arthur was a fortified naval base in the south of Manchuria that had been leased to Russia since 1898. After crushing the Boxer Rebellion as part of an eight-nation coalition, Russia infuriated Japan, which claimed parts of Manchuria within its own sphere of influence, by refusing to remove its troops. Japan was willing to recognise Russian dominance in Manchuria in return for access to Korea, but an agreement could not be reached and Japan broke off diplomatic relations on 6 February 1904.
Three hours before the Russian government received the declaration of war on 8 February, the Japanese Imperial Navy conducted a pre-emptive strike. Japanese Admiral Tōgō sent ten destroyers to Port Arthur where their torpedoes damaged two of the Russian fleet’s most powerful battleships as well as a cruiser. Although none of the ships were sunk due to the effectiveness of torpedo nets in the port, the Russian fleet was seriously weakened as the ships that had been hit were put out of action. The attack was halted at around 2am the following morning after the Russians turned on their searchlights and began to return fire.
At around 8am Admiral Tōgō sent a reconnaissance mission through the morning mist to inspect Port Arthur. With his observers reporting that the Russian fleet had been crippled by the previous night’s attack, the Japanese fleet were ordered to launch an attack on the port. In reality the reconnaissance was wrong and the Russians were prepared for battle. The Battle of Port Arthur resulted in ships on both sides suffering damage before the Japanese fleet retreated.