The opening stage of the Russo-Japanese War began with pre-emptive strikes by the Imperial Japanese Navy against the Russian Pacific Fleet based at Port Arthur and at Chemulpo. Admiral Tōgō's initial plan was to swoop down upon Port Arthur with the 1st Division of the Combined Fleet, consisting of the six pre-dreadnought battleships , , , , and , led by the flagship , and the 2nd Division, consisting of the armored cruisers , , , , and . These capital ships and cruisers were accompanied by some 15 destroyers and around 20 smaller torpedo boats. In reserve were the cruisers , , , and . With this large, well-trained and well-armed force, and surprise on his side, Admiral Tōgō hoped to deliver a crushing blow to the Russian fleet soon after the severance of diplomatic relations between the Japanese and Russian governments.