Oyama, Prince Iwao (1842–1916), commander in chief of Japanese armies in Manchuria in the Russo-Japanese War, 1904–05. He won the battles of Liaoyang, Shaho, and Mukden. Oyama was an observer with the Prussian army in the Franco-Prussian War and in 1877 commanded a brigade against his cousin Saigo Takamori in the Satsuma Rebellion. He was minister of war, 1880-95. In the war against China, 1894–95, Oyama's forces captured Port Arthur and Weihaiwei. He became a marquis and field marshal, and after the Russo-Japanese War was awarded the title of prince.