The Russian Empire
The Russian Empire was one of the major powers in the 19th century. It actively expanded the empire and tried to increase the influence on other weak nations. In Central Asia, the Russian Empire and Great Britain played "the Great Game" in order to gain the control of that area and to build bigger empires. At the same time, the Russian Empire also paid a lot attentions to the Eastern Asia and played a really important role in that area because of its expansions and interactions with China and Japan.
In Eastern Asia, Russia tried to gain territories from China and build a strong control over the Eastern Asia. By signing the Treaty of Aigun and participating in the Russo-China of Convention of Beijing, the Russian Empire annexed massive territories from China and put parts of Northern China into its spheres of influence. In 1891, the Russian Empire even started to build the Trans-Siberian Rail road which helped to extend the influence of Russian Empire to Eastern Asia. By founding Vladivostok and controlling Port Arthur(Lushunkou), the Russian Empire got access to the Pacific Ocean and increased its power in Eastern Asia. The imperialism brought huge benefits to the Russian Empire and caused the weakness of Qing Dynasty in China.
However, Russia still faced an strong enemy, Japan, which rapidly grew into world power during late 19th century. Both nations were interested in extending their power in Eastern Asia, particularly in China. After Japan defeated China in the Sino-Japanese War, Japan started to pay more attentions to its interests in Eastern Asia. As a result, the Russo-Japanese War, a conflict between two imperialistic powers, eventually broke off. Unfortunately, Russia was badly defeated in the war and humiliated by Japan. This later caused the internal revolutions in Russia and the end of the empire. However, Russia used to be a crucial imperialistic power in Eastern Asia throughout the 19th century.