Since Xinjiang is a popular topic, let me drop another spicy take. The Chinese have the older historical claim to the land and the Uighurs are the invaders. The situation is actually quite analogous to England actually, though in an England in which the Roman Empire never died.
The Uighurs themselves are not entirely autocthonous to the region, being an admixed population consisting of a native Western Eurasian (Iranian) component and a latter Eastern Eurasian (Turk) component. They are essentially the Anglo-Saxons redux. An outside barbarian group
subjugated the natives and through intermarriage at saber point wiped out the original culture and replaced it with their own just as the Germanic invasion of Britain subjugated the native celts. The thing was, the Han were there before the Barbarians ever showed up in the first
century BCE and have kept an intermittent presence for centuries afterward that was solidified in the 18th century via the genocide of the last wave of Mongol overlords of Dzungaria-Altishahr. The Uighurs are culturally quite alien to the original Iranic inhabitants of the region
having switched from Tocharian to Qarluk Turkish, from Buddhism to Islam, and of course the big change in race. So in summary, sassanachs out of Britain, Londinium rightful Roman clay.😠
