Manchuria is the region of northeastern China that now covers the provinces of Heilongjiang, Jilin and Liaoning. Some geographers also include northeastern Inner Mongolia, as well.
Manchuria is the traditional land of the Manchu, Xianbei, Khitan, and Jurchen peoples. The Manchus conquered all of China in 1644, and established the last Imperial Chinese Dynasty, the Qing, which lasted until 1911.
After the fall of the Qing Dynasty, Manchuria was conquered by the Japanese, who held it until the end of World War II.
"In the Treaty of Nerchinsk (1689), Russia was awarded the area that is sometimes called Outer Manchuria, north of the Stanovoy Mountains."