Tibet, or
Greater Tibet, is a region in the western part of East Asia, covering much of the Tibetan Plateau and spanning about 2,500,000 km
2 (970,000 sq mi). It is the homeland of the Tibetan people. Also resident on the plateau are other ethnic groups such as Mongols, Monpa, Tamang, Qiang, Sherpa, Lhoba, and since the 20th century Han Chinese and Hui. After the annexation of Tibet by the People's Republic of China in 1951, the entire plateau has been under the administration of the People's Republic of China. Tibet is divided administratively into the Tibet Autonomous Region and parts of the Qinghai, Gansu, Yunnan and Sichuan provinces. Tibet is also constitutionally claimed by the Republic of China as the Tibet Area since 1912. Tibet is the highest region on Earth, with an average elevation of 4,380 m (14,000 ft). Located in the Himalayas, the highest elevation in Tibet is Mount Everest, Earth's highest mountain, rising 8,848 m (29,000 ft) above sea level.