The Russo-Japanese War was a conflict fought between 1903 and 1905 over the competing imperial ambitions of the Russian Empire and the Empire of Japan. With Japan fresh off of a victory the prior decade in the First Sino-Japanese War, it became involved in a lengthy, bloody conflict with Russia over control of Korea, Manchuria and overall influence in weakened China, which was still reforming its military after its humiliating defeat to Japan in the 1890s.