well, when was manchuria a part of Korea?
Han-Chinese had lived in South Manchuria when Alexander conquered the greece world.
North manchuria and outer Manchuria occupied by Russia are the homeland of Manchus.
Now Manchus are completely sinicized...even more sinicized than Han-Chinese....
A long time ago. It was during when Korea was three kingdoms, Gorguyeo, Baeckhe, and Shilla. Gorguyeo stretched into China, which is Manchuria. When China took it over, they did not care at the time. It is one of my basis to think that there were other people in the three kindgoms.