Banners were first used during the Qing Dynasty, which organized the Mongols into banners except those who belonged to the Mongol Eight Banners. Each banner had sumun as nominal subdivisions, which also means arrow. In Inner Mongolia, several banners made up a league. In the rest, including Outer Mongolia, northern Xinjiang and Qinghai, ayimagh was the largest administrative division. While it restricted the Mongols from crossing banner borders, the dynasty protected Mongolia from population pressure from China proper.
Autonomous regions, prefectures, counties, and banners are covered under Section 6 of Chapter 3 (Articles 111-122) of the Constitution of the People's Republic of China, and with more detail under the Law of the People's Republic of China on Regional National Autonomy (《中华人民共和国民族区域自治法》).
Xinjiang was converted from a province to an autonomous region in 1955.
Autonomous administrative areas, as well as the various rights granted to them, are affirmed by the government as a positive example of local self-rule in ethnic areas, and an acknowledgement of minority self-determination unprecedented in Chinese history.
In October 1955, the Xinjiang Uygur Autonomous Region was established; in March 1958, the Guangxi Zhuang Autonomous Region was established; in October 1958, the Ningxia Hui Autonomous Region was established; and in September 1965, the Tibet Autonomous Region was established.
The head of an autonomous region, autonomousprefecture or autonomouscounty shall be a citizen of the ethnic group exercising regional autonomy in the area concerned.
The heads of all autonomous regions, autonomousprefectures and autonomouscounties are all citizens of the ethnic groups exercising regional autonomy in the areas concerned.