'Uighur' is  relatively new word.A certain persian speaking people(still there,numbered at about 80,000 I guess),not the Uighurs, are the original aborigines of Xinjiang.Uiighurs are turk/mongol descendents

Chinese have a long history in central asia. Two prominent examples:

--Mulan the semi-fictional heroine  apparently was not a han.She was a camel jockey who called the chinese Emperor the 'Great Khan'.She was likely the daughter of a local tribune who served the chinese emperor.

--Li Bao,the chinese poet  laureate,was born in present day Kyrgystan.There's even a street there named after him.