On February 8, 1904 (Meiji 37), the Japanese Imperial fleet under the command of Admiral Heihachiro Togo (東郷平八郎, 1848–1934) opened the Russo-Japanese War (1904–1905) with a surprise attack on the Russian ships at Port Arthur (current Lüshunkou).
The conflict was the result of rivalry over Manchuria and Korea by the Russian Empire and the Empire of Japan. The war was mainly fought in Southern Manchuria and the seas around Korea, Japan, and China. The total number of army dead is estimated at 130,000 to 170,000, while China counted some 20,000 civilian deaths.
American President Theodore Roosevelt offered to mediate when Tsar Nicholas II elected to negotiate peace and on September 5, 1905 (Meiji 38), the Treaty of Portsmouth was signed.
It was the first time in the modern era that an Asian nation militarily defeated a European nation. It greatly shocked the world, and raised Japan’s prestige greatly. It would also eventually lead to the outbreak of hostilities between China and Japan and the Pacific War.