I.

Introduction

Russo-Japanese War, armed conflict between Russia and Japan in 1904-1905. The cause of the war was that Russian expansion in eastern Asia ran counter to Japanese plans for gaining a foothold on the Asian mainland. Russia and other European powers had already stopped Japan establishing control over Korea after the Sino-Japanese War (1894-1895). In 1898 Russia leased Port Arthur from China, with the intention of making it a great Asiatic port and the headquarters of Russian naval power in the Pacific. Russia had poured troops into Dongbei during the Boxer Rebellion in 1900 but, faced with the Anglo-Japanese alliance of 1902, promised to leave Chinese territory. The promise was not kept, however, and in June 1903 Japan proposed a mutual agreement recognizing Japan's interests in Korea and Russia's in Dongbei, and ensuring the integrity of China and Korea. Russia refused. On the night of February 8, 1904, the Japanese navy launched a surprise attack on Port Arthur and then blockaded the damaged Russian fleet. Japan's formal declaration of war followed on February 10.