Korean Empire
The Korean Empire (Daehan Jeguk, ) lasted between 1897 and 1910. It was the last time Korea was unified and independent. The empire was established when the king Gojong became an emperor. After the First Sino-Japanese War, Korea was no longer a Chinese tributary state. But then in 1907 Korea became a Japanese protectorate, and 1910, got annexed by Japan as the province of Choson. Korea became a Japanese colony until 1945. Then after the Korean War it split.