[TigersEye]

Of course this is a situation like Britain claiming the American colonies that were largely populated from its own population.

It's even more remote than that. It's more like Norwegians claiming that they used to rule Britain because Vikings had, at one time, a foothold in what eventually became Britain. There was nothing even remotely resembling a single country called China in 3,000 BC and 'northern China' could easily be thought of as Mongol territory (depending upon how 'northern' we're talking about) assuming there was anything resembling a pre-Mongolian culture that far back.

[HiTech RedNeck]

It seems pretty clear here that within the scope of what China calls its history life (6000 years), Northern Chinese didn’t just “get a foothold” in Tibet, they outnumbered any previous inhabitants.

Now when China effectively relinquished Tibet (so much is not said about the independence years, but I assume China just didn’t want to bother), should that count for good? Being a native of a young country I would say yes by the standards I know, but it’s probably more kind of like how China thinks of Taiwan.