"Xinjiang" or "Ice Jecen" in Manchu, literally means "New Frontier", a name given during the Manchu Qing Dynasty in China. It is home to a number of different ethnic groups, many of them Turkic, the largest of which is the Uyghur people. Older English-language reference works often refer to the area as Chinese Turkestan, Sinkiang, East Turkestan, or Uyghuristan.

The east-west Tien Shan Mountains separate Dzungaria in the north from the Tarim Basin in the south. Dzungaria is dry steppe. The Tarim Basin is desert surrounded by oases. In the east is the Turfan Depression. In the west, the Tien Shan split, forming the Ili River valley.

The Qing Empire, established by the Manchus in China, gained control over eastern Xinjiang as a result of a long struggle with the Zunghars (Dzungars) that began in the seventeenth century. In 1755, the Manchu Empire attacked Ghulja, and captured the Zunghar khan. Over the next two years, the Manchus and Mongol armies of the Qing destroyed the remnants of the Zunghar khanate, and attempted to divide the Xinjiang region into four sub-khanates under four chiefs. Similarly, the Qing made members of a clan of sufi shaykhs known as the Khojas, rulers in the western Tarim Basin, south of the Tianshan Mts. In 1758-59, however, rebellions against this arrangement broke out both north and south of the Tian Shan mountains. The Qing was thus forced, contrary to its initial intent, to establish a form of direct military rule over both Zungharia (northern Xinjiang) and the Tarim Basin (southern Xinjiang). The Manchus put the whole region under the rule of a General of Ili, headquartered at the fort of Huiyuan (the so-called "Manchu Kuldja", or Yili), 30 km west of Ghulja (Yining).

By the mid-19th century, the Russian Empire was encroaching upon Qing China along its entire northern frontier. The Opium Wars and Taiping and other rebellion's in China proper had severely restricted the dynasty's ability to maintain its garrisons in distant Xinjiang. In 1864 both Chinese Muslims (Hui) and Uyghurs rebelled in Xinjiang cities, following an on-going Chinese Muslim Rebellion in Gansu and Shaanxi provinces further east. Qing control of the region was swept away. In 1865, Yaqub Beg, a warlord from the neighbouring Khanate of Kokand, entered Xinjiang via Kashgar, and conquered nearly all of Xinjiang over the next six years. In 1871, Russia took advantage of the chaotic situation and seized the rich Ili River valley, including Gulja. By then, Qing China held onto only a few strongholds, including Tacheng.

Yaqub Beg's rule lasted until General Zuo Zongtang (also known as General Tso) reconquered the region between 1875 and 1877 for Qing China. In 1881, Qing China recovered the Gulja region through diplomatic negotiations (Treaty of Saint Petersburg (1881)). In 1884, Qing China established Xinjiang ("new frontier") as a province, formally applying onto it the political system of China proper.

Xinjiang is the largest political subdivision of China — it accounts for more than one sixth of China's total territory and a quarter of its boundary length. It is divided into two basins by Mount Tianshan. Dzungarian Basin is in the north, and Tarim Basin is in the south. Xinjiang's lowest point is the Turfan Depression, 155 metres below sea level (lowest point in the PRC as well). Its highest peak, K2, is 8611 metres above sea level, on the border with Kashmir.

Close to Karakoram Highway in Xinjiang. Most of Xinjiang is young geologically, having been formed from the collision of the Indian plate with the Eurasian plate, forming the Tian Shan, Kunlun Shan, and Pamir mountain ranges. Consequently, Xinjiang is a major earthquake zone. Older geological formations occur principally in the far north where the Junggar Block is geologically part of Kazakhstan, and in the east which is part of the North China Craton.