Original sentence: The Xinjiang Wars were a series of armed conflicts which took place in the early and mid 20th century, during the Warlord Era of the Republic of China; and during the Chinese Civil War, which effectively resulted in the controversial de facto establishment of the People's Republic of China
Edited sentence: The Xinjiang Wars were a series of armed conflicts which took place in the early and mid 20th century, during the Warlord Era of the Republic of China; and during the Chinese Civil War, which saw the establishment of the People's Republic of China