"When did this occur, who were these folks and where were they from. Your estimates of those questions is okay, I'm not expecting exactness. (I'm interested in this area...could they have been Hakka? Xiongnu?)"
Under normal circumstances I *could* give you pretty exact details, but I moved in late 2002, and my books are still mostly packed.
According to a page I turned up on a google search, the Manchu took over China in 1644.
Another site (
http://www.warriortours.com/intro/history/qing/) states:
"The Jurchen people, believed to be the ancestors of the Manchus, had been a nomadic tribe that lived adjacent to the present Heilongjiang region. In the closing years of the Ming Dynasty (1368 - 1644), a great leader named Nurhachi, emerged from the Jurchen tribe. Under his leadership, the Jurchen people rapidly united and in 1616, established the Later Jin State which was independent from the Ming. In 1636, Nurhachi's son Abahai, renamed the dynasty as Qing in Shenyang while formally declaring war on the Ming."
I think the Ming started feeling pressure from the Manchu about 1500, although it got more serious later.
Apologies for not being more exact.