The Sino-Japanese War was a conflict between the Empire of Japan and the Qing dynasty of China that lasted from 1894 to 1895. It was fought over control of Korea, which was then a tributary state of China. The war began with a Japanese invasion of the Liaodong Peninsula in Manchuria and ended with the Treaty of Shimonoseki, which ceded the peninsula to Japan. The Russo-Japanese War was a conflict between the Russian Empire and the Empire of Japan that lasted from 1904 to 1905. It was fought over control of Manchuria and Korea, which were both under Russian influence at the time. The war began with a Japanese surprise attack on the Russian Pacific Fleet at Port Arthur and ended with the Treaty of Portsmouth, which ceded the southern half of Sakhalin Island to Japan.