Qinghai (; pronounced ), also known as Kokonor and Tsogon, is a province of the People's Republic of China located in the northwest of the country. As one of the largest province-level administrative division of China by area, the province is ranked fourth-largest in size, but has the third-smallest population. Located mostly on the Tibetan Plateau, the province is home to a large population of ethnic Tibetans and it roughly corresponds with Amdo, one of the three traditional provinces of cultural Tibet. The majority Han Chinese mostly live in the provincial capital of Xining to the north east. Qinghai borders Gansu on the northeast, the Xinjiang on the northwest, Sichuan on the southeast, and the Tibet Autonomous Region on the southwest.
The Chinese name, "Qinghai" is named after Qinghai Lake (cyan lake), the largest lake in China. The province was known formerly as Kokonur in English, derived from the Oirat name for Qinghai Lake. Qinghai is known as Tsongon in Tibetan.
During China's Bronze Age, Qinghai was home to the Qiang people who traditionally make living in agriculture and husbandry, the Kayue culture. The eastern part of the area of Qinghai was under the control of the Han Dynasty about 2000 years ago. It was a battleground during the Tang and subsequent Chinese dynasties when they fought against successive Tibetan tribes.
In the middle of 3rd century CE, nomadic people related to Xianbei migrated to pasture lands around Koko Nur (Qinghai Lake) and established Tuyuhun Kingdom. Since the 7th century, Tuyuhun Kingdom was attacked by both the Tibetan Empire and Tang Dynasty as both of them sought control over trade routes. Military conflicts severely weakened the kingdom and it was incorporated into the Tibetan Empire. After the disintegration of the Tibetan Empire, small local factions emerged. They were under titular authority of China and Tibet but maintained their autonomy. During the period of Mongol Yuan Dynasty's administrative rule of Tibet, majority of Qinghai belonged to one of the three commandaries of the Tibetan region divided at that time, namely Amdo (Tibetan: ཨ༌མདོ; Chinese: 安多; pinyin: Ānduō).
The Xunhua Salar Autonomous County is where the Salar people live in Qinghai. The Salars voluntarily joined the Ming Dynasty. The Salar clan leaders each capitulated to the Ming Dynasty around 1370. The chief of the four upper clans around this time was Han Pao-yuan and Ming granted him office of centurion, it was at this time the people of his four clans took Han as their surname. The other chief Han Shan-pa of the four lower Salar clans got the same office from Ming, and his clans were the ones who took Ma as their surname.
From the late Ming to 1724, a big part of the area that is now Qinghai was under Khoshut Mongol control, but in that year it was conquered by the armies of the Qing Dynasty. It was during 1720s when Xining Prefecture was established and its borders were roughly those of modern Qinghai province. Xining, the capital of modern Qinghai province was built in this period as the administrative center. During the rule of Qing Dynasty, the governor was a viceroy of the Qing Emperor, but the local ethnic groups enjoyed much autonomy. Many chiefs retained their traditional authority, participating in local administrations. The Dungan revolt (1895–1896) broke out in Qinghai in 1895. The Dungan Revolt (1895) was a rebellion of various Muslim ethnic groups in Qinghai and Gansu against the Qing Dynasty. Following the overthrow of the Qing Dynasty, the region came under Chinese Muslim warlord Ma Qi control until the Northern Expedition by the Republic of China consolidated central control in 1928.
In 1928, Qinghai province was created. Previoiusly, it was part of Gansu province, as the "Tibetan frontier district".
In 1932 Tibet invaded Qinghai, attempting to capture southern parts of Qinghai province, following contention in Yushu, Qinghai over a monastery in 1932. The army of Ma Bufang's defeated the Tibetan armies.
Governor of Qinghai, Ma Bufang was described as a socialist by American journalist John Roderick and friendly compared to the other Ma Clique warlords. Ma Bufang was reported to be good humoured and jovial in contrast to the brutal reign of Ma Hongkui.
Ma Bufang increased the prominence of the Hui and Salar people in Qinghai's politics by heavily recruiting to his army from the counties in which those ethnic groups predominated. General Ma started a state run and controlled industralization project, directly creating educational, medical, agricultural, and sanitation projects, run or assisted by the state. The state provided money for food and uniforms in all schools, state run or private. Roads and a theater were constructed. The state controlled all the press, no freedom was allowed for independent journalists. His regime was dictatoral in its political system. Barnett admitted that the regime had "sterm authoritarianism" and "little room for personal freedom".
After the 1949 Chinese revolution, control over Qinghai acceded from the Republic of China to the People's Republic of China. Kuomintang resistance in Qinghai by Ma Bufang and Ma Jiyuan was defeated in the Lanzhou Campaign. Aside from some minor adjustments to suit the geography, the PRC maintained the province's territorial integrity.