Evidence of human habitation dating between 12,000 and 11,000 years ago has been found in NW Tibet, and in S Tibet the Yarlung Zangbo valley was, over the centuries, the focus of ancient trade routes from India, China, and Central Asia. Tibet emerged from an obscure history to flourish in the 7th cent. A.D. as an independent kingdom with its capital at Lhasa. The Chinese first established relations with Tibet during the T'ang dynasty (618–906), and there were frequent wars of conquest. The Tibetan kingdom was associated with early Mahayana Buddhism, which the scholar and mystic Padmasambhava fashioned (8th cent.) into Tibetan Buddhism. Toward the end of the 12th cent. many Indian Buddhists, fleeing before the Muslim invasion, went to Tibet. In the 13th cent. Tibet fell under Mongol influence, which was to last until the 18th cent. In 1270, Kublai Khan, emperor of China, was converted to Buddhism by the abbot of the Sakya lamasery; the abbot returned to Tibet to found the Sakya dynasty (1270–1340) and to become the first lama to rule Tibet. In 1720, the Ch'ing dynasty replaced Mongol rule in Tibet. China thereafter claimed suzerainty, often merely nominal.
During the 18th cent., British authorities in India attempted to establish relations with Lhasa, but the Gurkha invasion of 1788 and the subsequent Gurkha war (1792) with Tibet brought an abrupt end to the rapprochement. Jesuits and Capuchins had visited Tibet in the 17th and 18th cent., but throughout the 19th cent. Tibet maintained its traditional seclusion. Meanwhile, Ladakh, long part of Tibet, was lost to the rulers of Kashmir, and Sikkim was detached (1890) by Britain. In 1893, Britain succeeded in obtaining a trading post at Yadong, but continued Tibetan interference led to the military expedition (1904) of Sir Francis Younghusband to Lhasa, which enforced the granting of trade posts at Yadong, Gyangzê, and Gar.
In 1906 and 1907, Britain recognized China's suzerainty over Tibet. However, the Tibetans were able, with the overthrow of the Ch'ing dynasty in China, to expel (1912) the Chinese in Tibet and reassert their independence. At a conference (1913–14) of British, Tibetans, and Chinese at Shimla, India, Tibet was tentatively confirmed under Chinese suzerainty and divided into an inner Tibet, to be incorporated into China, and an outer autonomous Tibet. The Shimla agreement was, however, never ratified by the Chinese, who continued to claim all of Tibet as a "special territory." After the death (1933) of the 13th Dalai Lama, Tibet gradually drifted back into the Chinese orbit. The 14th Dalai Lama, who was born in China, was installed in 1939–40 and assumed full powers (1950) after a ten-year regency.
The succession of the 10th Panchen Lama, with rival candidates supported by Tibet and China, was one of the excuses for the Chinese invasion (Oct., 1950) of Tibet. By a Tibetan-Chinese agreement (May, 1951), Tibet became a "national autonomous region" of China under the traditional rule of the Dalai Lama, but under the actual control of a Chinese Communist commission. The Communist government introduced far-reaching land reforms and sharply curtailed the power of the monastic orders. After 1956 scattered uprisings occurred throughout the country, but a full-scale revolt broke out in Mar., 1959, prompted in part by fears for the personal safety of the Dalai Lama. The Chinese suppressed the rebellion, but the Dalai Lama was able to escape to India, where he eventually established headquarters in exile.
The Panchen Lama, who had accepted Chinese sponsorship, acceded to the spiritual leadership of Tibet. The Chinese adopted brutal repressive measures, provoking charges from the Dalai Lama of genocide. Landholdings were seized, the lamaseries were virtually emptied, and thousands of monks were forced to find other work. The Panchen Lama was deposed in 1964 after making statements supporting the Dalai Lama; he was replaced by a secular Tibetan leader. In 1962, China launched attacks along the Indian-Tibetan border to consolidate territories it claimed had been wrongly given to India by the British McMahon Commission in 1914. Following a cease-fire, Chinese troops withdrew behind the disputed line in the east but continued to occupy part of Ladakh in Kashmir. Some border areas are still in dispute.
In 1965 the Tibetan Autonomous Region was formally established. The Cultural Revolution, with its antireligious orientation, was disastrous for highly religious Tibet. Religious practices were banned and over 4,000 monasteries were destroyed. Though the ban was lifted in 1976 and some Buddhist temples have again been in operation since the early 1980s, Tibetans continue to complain of widespread discrimination by the Chinese, and in more recent years the sometimes forcible relocation of Tibetans from traditional communities to new housing developments has contributed to dissatisfaction. Several protests in Tibet in the late 1980s and early 1990s were violently suppressed by the Communist government and martial law was imposed in 1989. Demonstrations against Chinese rule have nevertheless continued, and other countries have increasingly raised the issue of human-rights violations in Tibet and pressured the Chinese government to moderate their stance in the region. Religious tensions were again underscored in 1995 when China rejected the boy who was confirmed by the Dalai Lama as the new Panchen Lama and forced the selection of a different boy and in 2000 when the 14-year-old Karmapa lama fled Tibet for India. Significant new protests and riots erupted in Tibet and among Tibetans in neighboring provinces in 2008 and to a lesser degree in Tibet in 2012.