https://en.wikipedia.org/wiki/History_of_Sino-Korean_relations
''Under Emperor
Hong Taiji, the
Manchuria-based
Qing dynasty invaded Korea twice, in 1627 and 1636. Following the
Second Manchu invasion of Korea, the Qing claimed victory and forced
Injo of Joseon into submission, severing its relations with the collapsing Ming dynasty, which eventually fell in 1644. Qing China's national strength gradually declined after its defeat in the
First and
Second Opium Wars. As such, China was forced to sign a series of concessions and
unequal treaties with the Western colonial powers. At the same time, the
Meiji Restoration occurred in Japan and led to the rise of the
Empire of Japan, which gradually expanded its military power. The
Donghak Peasant Revolution of Korea in 1894 became a catalyst for the
First Sino-Japanese War, which saw the defeat of the Qing military. As part of the terms in the post-war
Treaty of Shimonoseki, China recognized the independence of Korea and ceased its tributary relations. The
Korean Empire established modern diplomatic relationship with Qing, but Korea was eventually "annexed," against their will, by Japan under the
Japan–Korea Treaty of 1910.''
There I am too lazy, so here are my copy-paste facts. Korea was sort of puppet government under Qing dynasty for some time in the past.