Hexi Corridor
The Hexi Corridor, also known as the Gansu Corridor, is an important historical region located in the modern western Gansu province of China. It refers to a narrow stretch of traversable and relatively arable plain west of the Yellow River's Ordos Loop, flanked between the much more elevated and inhospitable terrains of the Mongolian and Tibetan Plateaus.
As part of the Northern Silk Road, running northwest from the western section of the Ordos Loop between Yinchuan and Lanzhou, the Hexi Corridor was the most important trade route in Northwest China. It linked China proper to the historic Western Regions for traders and military incursions into Central Asia. It is a string of oases along the northern edges of the Qilian Mountains and Altyn-Tagh, with the high and desolate Tibetan Plateau further to the south. To the north are the Longshou, Heli and Mazong Mountains separating it from the arid Badain Jaran Desert, Gobi Desert and the cold steppes of the Mongolian Plateau. At the western end, the route splits into three, going either north of the Tianshan Mountains or south on either side of the Tarim Basin. At the eastern end, the mountains around Lanzhou grants access to the Longxi Basin, which leads east through Mount Long along the Wei River valley into the populous Guanzhong Plain, and then into the Central Plain.
Geography
The Hexi Corridor is located in western Gansu Province. It stretches roughly from the Wushao Mountains in the east to Yumen Pass in the west, from north to south, ranges from in width, and covers an area of approximately or around 60% of the area of Gansu Province. Its population was 4.82 million people in 2011, representing around 19% of the province's total population. As of 2024, the corridor contains 20 administrative divisions and five prefecture-level cities, which are, from east to west: Wuwei, Jinchang, Zhangye, Jiuquan, and Jiayuguan.The elevation of the Hexi Corridor descends from around above sea level in the southeast to in the northwest, and is internally divided by three uplifts into four intermontane basins. It is bordered by the Qilian Mountains in the south and southeast, the Kumtag Desert to the west, the Mazong, Helan, and Longshou Mountains to the north, the Badain Jaran Desert to the northeast, and the Tengger Desert to the southeast. The Qilian Mountains run south of the Hexi Corridor for and contain several peaks exceeding above sea level, while the mountains to the north generally range from in height.
Three major inland rivers flow through the Hexi Corridor: the Shiyang, Heihe, and Shule rivers. These rivers originate from the melting of glaciers and snow in the Qilian Mountain and form extensive alluvial fans and inland drainage basins in their lower reaches, beyond which lie deserts and large sand dune fields. Arable land in the Hexi Corridor mainly consists of regions around the oases that form in the deserts and around the rivers, which have supported both nomadic populations and settled civilizations for millennia.
History
Prehistory
The Hexi Corridor has been the site of cultural exchanges across Eurasia since prehistory. It was first settled around 4800BP in Neolithic times by millet farmers from the Yangshao Culture in the western Loess Plateau, who enabled the spread of millet to Central Asia and the rest of Eurasia and Africa. These farmers also used pottery production techniques from Northern China. Several cultures developed in the Hexi corridor during this time, such as the Majiayao, Banshan, and Machang.The oldest known bronze object discovered in China, dating to 5000–4500 BP, was unearthed at the Majiayao site. The introduction of copper-smelting technology around 4200 BP marked the beginning of the Bronze Age in the Hexi Corridor, and bronze production reached its peak between 4000 and 3500 BP. Bronze artifacts from the Hexi Corridor dating to this period account for approximately 70 percent of all bronze objects found in China prior to the Shang dynasty. During this time, domesticated livestock were introduced to the region, so local cultures such as the Shajing, Qijia, Xichengyi, Siba, and Shanma developed agricultural economies based on smelting copper, cultivating millet, and herding animals such as sheep, pigs, cattle, and horses.
Wheat and barley from the Fertile Crescent arrived in the Hexi Corridor via Central Asia around 4000 BP, and later spread into China proper. By around 3700–3500BP, most likely due to the continual weakening and retreat of the East Asian monsoon since 4000BP which had caused increasing aridity, the more drought-resistant wheat and barley had replaced millet as the main staple crop in the Hexi Corridor. Cultures after this time period saw a decrease in site numbers and bronze artifacts, and became dominated by nomadic production rather than agriculture.
Han dynasty
The nomadic Yuezhi resided in the Hexi Corridor in the 3rd centuryBCE. The Great Wall of China was constructed into parts of the Hexi Corridor following the Qin-Xiongnu Wars, and the defeated Xiongnu formed a confederacy under leader Modu Chanyu. In 176BCE, the Xiongnu defeated the Yuezhi, most of whom fled from the region while the remaining population moved south into the Qilian Mountains to live with the Qiang. The Xiongnu were subsequently in complete control of the Hexi Corridor.During the Han-Xiongnu Wars, Han dynasty general Huo Qubing expelled the Xiongnu from the Hexi Corridor at the . The province of Liangzhou was created with its capital at Guzang, within which the commanderies of Wuwei, Zhangye, Jiuquan and Dunhuang were established. This gave the Han dynasty control over major trade routes to Central Asia and is regarded by most scholars as the beginning of the Silk Road. Agricultural garrison towns were established in the Hexi Corridor to secure the route and the Great Wall was extended to Yumen Pass west of Dunhuang. Additionally, the Han dynasty's acquisition of the Hexi Corridor allowed them to conquer the Tarim Basin and establish the Protectorate of the Western Regions in 60BCE, and proved instrumental in defeating the Xiongnu as it prevented contact between them and the Qiang.
File:Han_Dynasty_Granary_west_of_Dunhuang.jpg|left|thumb|350x350px|Ruins of the Big Fangpan Castle at Yumen Pass, the western end of the Han-era Great Wall.
Following the collapse of the interregnum Xin dynasty in 23CE, the Hexi Corridor was settled by large numbers of Qiang people and came under the control of warlord, who submitted to the reinstated Eastern Han dynasty in 29CE. In the 2nd century CE, millions of Han settlers withdrew from the Hexi Corridor when the Qiang began to raid the region. The Yuezhi, Xiongnu, and Qiang instigated the Liangzhou Rebellion in 184, which largely isolated the Hexi Corridor from central control and contributed to the fall of the Han dynasty. By the end of the Han dynasty, the Hexi Corridor was occupied by warlords Han Sui, Ma Teng and Ma Chao. In 214, warlord Cao Cao conquered the region and incorporated it into his state of Cao Wei.
Six Dynasties and Sixteen Kingdoms
Cao Cao's son Cao Pi of Wei deposed the Han dynasty in 220, marking the start of the Three Kingdoms era. In 230, rival Three Kingdoms state Shu Han attacked the Hexi Corridor as part of Zhuge Liang's Northern Expeditions. In 266, Cao Wei became the Jin dynasty, which inherited the Hexi Corridor. In 270, the Xianbei, related to the Xiongnu, began a rebellion in the region which lasted until 279. Starting in the late 3rd century, groups such as the Kushans and Sogdians established a widespread presence in the Hexi Corridor as merchants along the Silk Road. These groups contributed significantly to the spread of belief systems such as Buddhism into the Hexi Corridor.The state of Former Liang was founded in the Hexi Corridor in the early 4th century, and became the longest-lasting and most politically stable of the Sixteen Kingdoms. In 376, Former Liang was conquered by Former Qin; various parts of the Hexi Corridor then came under the control of Later Liang in 386, Southern and Northern Liang in 397, and Western Liang in 400, before reunifying under Northern Liang in 421. During this period, the Hexi Corridor was spared from much of the turmoil of the Central China Plains, which caused increased migration to the region and led to it becoming a centre of culture in China. Buddhist culture and activity flourished in the region; the first of the Mogao Caves were constructed during this time, and the extensive creation of Buddhist artworks and translation of texts at this time directly contributed to the adoption of the religion in the rest of China.
In 439, Northern Wei conquered Northern Liang and ended the Sixteen Kingdoms era, though the final Northern Liang stronghold at Dunhuang remained until 442. A garrison was then established at Dunhuang to defend against the Rouran and significant numbers of civilians were moved from the Hexi Corridor to the Wei capital at Pingcheng, promoting the readoption of classical Chinese culture and spread of Buddhism in the Central Plains. In the 470s, the Northern Wei government considered abandoning the Hexi Corridor due to repeated raids by the Rouran. They later defeated the Rouran in 492, although the region remained largely desolate into the early 6th century. After the fall of Northern Wei, the Hexi Corridor came into the control of Western Wei in 535, which became Northern Zhou in 557.
Medieval history
In 581, Northern Zhou became the Sui dynasty, which later reunited China Proper for the first time in three centuries. In 609, Emperor Yang of Sui toured the region and personally commanded an expedition against the Tuyuhun to protect its trade routes. Warlord Li Gui seized control of the Hexi Corridor in 617 and proclaimed himself ruler of Liang, which was conquered by the newly-founded Tang dynasty in 619. In 627, Buddhist monk Xuanzang passed through the Hexi Corridor on his way to India.Between 630 and 657, the Tang dynasty conquered territories from several Central Asian states to secure the Hexi Corridor and consolidate control over the Silk Road. The renewed stability encouraged trade and cultural exchange; goods as well as religions such as Zoroastrianism, Nestorian Christianity, and Islam spread through the region into central China, and cities in the Hexi Corridor became increasingly cosmopolitan. This expansion also brought the Tang into conflict with the Tibetan Empire, which began encroaching on the Hexi Corridor around 670. In 711, the Hexi Corridor was organised under a military governor as one of nine frontier commands of the Tang dynasty, which by 742 possessed a quarter of all horses in the empire and represented its third-largest military force.
Tang forces were withdrawn from the Hexi Corridor following the outbreak of the An Lushan Rebellion in 755 and the Tibetan Empire gradually occupied the region, culminating in their capture of Dunhuang in 786 and the rest of the Hexi Corridor in the 790s. Following this, residents of the region adopted various Tibetan customs such as the use of Tibetan names and the Tibetan script, which continued even after the Tang dynasty reasserted control. Tibetan influence in the Hexi Corridor during this period led to the spread of Tibetan Buddhist culture to the rest of Eurasia, where it remained a dominant culture into the early 20th century.
The Tibetan Empire collapsed in 842; the Hexi Corridor was then seized by warlord Zhang Yichao in 848, who established the Tang-loyal Guiyi Circuit in 851. The Guiyi Circuit reunified the Hexi Corridor and reached its greatest extent in the 860s. Its power and territory then steadily declined under pressure from two Uyghur states: the Qocho Kingdom in the Tarim Basin to the west and the Ganzhou Uyghur Kingdom to the east, which was founded after the Guiyi Circuit lost control of its eastern provinces in the 880s.
By the early 10th century, the Guiyi Circuit was confined to the area surrounding Dunhuang, and was almost completely isolated from the rest of China by the Ganzhou Uyghurs' seizure of goods along the Silk Road. In 911, the Guiyi Circuit became a vassal of the Ganzhou Uyghurs and reopened the Silk Road in 925. After this, Dunhuang once again became a centre of culture in the region; some of the largest temples at the Mogao Caves were constructed during this time, and Buddhist texts produced at Dunhuang were freely distributed to the Ganzhou and Qocho kingdoms. This revival was partly driven and financed by the diplomatic relations that the three states maintained with one another and with the dominant dynasties of the Central Plains.