Guanzhong in the context of Shanxi Rift System

Xi'an is the capital of the Chinese province of Shaanxi. A sub-provincial city on the Guanzhong plain, the city is the third-most populous city in Western China after Chongqing and Chengdu, as well as the most populous city in Northwestern China. Its total population was 12.95 million in the 2020 census, including an urban population of 9.28 million.

Xi'an is one of the oldest cities in China. Known as Chang'an throughout much of its history, Xi'an is one of China's Four Great Ancient Capitals, having held the position under several of the most important dynasties in Chinese history, including the Western Zhou, Qin, Western Han, Sui, Northern Zhou and Tang. Xi'an is now the second-most popular tourist destination in China. The city was one of the terminal points on the Silk Road during the ancient and medieval eras, as well as the home of the 3rd-century BC Terracotta Army commissioned by Emperor Qin Shi Huang—both of which are listed as World Heritage Sites by UNESCO.

Emperor Gaozu of Han (256 or 247 – 1 June 195 BC), personal name Liu Bang, was the founder and first emperor of the Han dynasty.

Liu Bang was among the few dynastic founders to have been born in a peasant family. He initially entered the Qin dynasty bureaucracy as a minor law enforcement officer in his hometown in Pei County, within the conquered state of Chu. During the political chaos following the death of Qin Shi Huang, who had been the first emperor in Chinese history, Liu Bang renounced his civil service position and became a rebel leader, taking up arms against the Qin dynasty. He outmanoeuvred rival rebel leader Xiang Yu to invade the Qin heartland and forced the surrender of the Qin ruler Ziying in 206 BC.

Shaanxi is a province in north Northwestern China bordering the province-level divisions of Inner Mongolia to the north; Shanxi and Henan to the east; Hubei, Chongqing, and Sichuan to the south; and Gansu and Ningxia to the west. Shaanxi covers an area of over 205,000 km (79,000 sq mi) with about 37 million people, the 16th-largest in China. Xi'an, which includes the sites of the former capitals Fenghao and Chang'an – is the provincial capital and largest city in Northwest China and also one of the oldest cities in China. It is also the oldest of the Four Ancient Capitals, being the capital for the Western Zhou, Western Han, Jin, Sui and Tang dynasties. Xianyang, which served as the capital of the Qin dynasty (221–206 BC), is just north across the Wei River. The other prefecture-level cities into which the province is divided are Ankang, Baoji, Hanzhong, Shangluo, Tongchuan, Weinan, Yan'an and Yulin.

The province is geographically divided into three parts, namely Northern (or "Shaanbei"), Central ("Shaanzhong") and Southern Shaanxi (or "Shaannan"). Northern Shaanxi makes up the southeastern portion of the Ordos Basin and mainly comprises the two prefectural cities of Yulin and Yan'an on the northern Loess Plateau, demarcated from the Ordos Desert and the grasslands of Inner Mongolia's Ordos City by the Ming Great Wall. Central Shaanxi is also known as the Guanzhong region, and comprises the drainage basin of lower Wei River east of Mount Liupan and north of the Qinling Mountains, where the majority of Shaanxi's population reside. Southern Shaanxi comprises the three prefectural cities in the edge of the historical Bashu region south of the Qinling Mountains and includes the three mountainous cities of Hanzhong, Ankang and Shangluo.

The Han–Xiongnu Wars or Sino-Xiongnu Wars, were a series of military conflicts fought from 133 BC to 89 AD between the agrarian Chinese Han Empire and the nomadic Xiongnu confederacy, although extended conflicts can be traced back as early as 200 BC and as late as 188 AD.

The Chinese civilization initially clashed with Inner Asian nomadic tribes (then collectively known as Di) that would later become the Xiongnu during the Warring States period, and various northern states built elongated fortifications (which later became the Great Wall) to defend against raids down from the Mongolian Plateau. The unified Qin dynasty, who conquered all other states under Emperor Qin Shi Huang, dispatched General Meng Tian in 215 BC in a successful campaign to expel the Xiongnu from the Ordos region (which was often used as a staging area to threaten Qin's Guanzhong heartland). However, the subsequent civil wars following the Qin dynasty's collapse gave the Xiongnu tribes, who were then unified into a large confederacy under Modu Chanyu, the opportunity to reinvade the Ordos region. After the Han dynasty was established in 202 BC, Emperor Gao tried to fight off Xiongnu invasions but had himself trapped in an ambush during the Battle of Baideng, and a truce was negotiated by bribing Modu's wife, thus ending first Han–Xiongnu War. Decades of de jure peace then followed with the Chinese gifting "harmony via marriage" to appease the Xiongnu, who still routinely raided Chinese borderlands.

Xia (Chinese: 夏; pinyin: Xià), known in historiography as Hu Xia (胡夏), Xiongnu Xia (匈奴夏), Helian Xia (赫連夏) or the Great Xia (大夏), was a dynastic state of China ruled by the Helian clan of Tiefu-Xiongnu ethnicity during the Sixteen Kingdoms period. Prior to establishing the Xia, the imperial clan existed as a tribal entity known as the Tiefu (simplified Chinese: 铁弗; traditional Chinese: 鐵弗; pinyin: Tiěfú).

All rulers of the Xia declared themselves "emperors". Both the Tiefu and Xia were based in the Ordos Desert, and during the reign of Helian Bobo, they constructed their capital of Tongwan, a heavily fortified and state-of-the-art city that served as a frontier garrison until the Song dynasty. Its ruins were discovered during the Qing dynasty and can still be seen in present-day Northern Shaanxi. At its peak, the Xia also controlled the Guanzhong region in modern-day central Shaanxi. Due to being a mix of the Xiongnu and Xianbei ethnicities, the Tiefu were initially known as a group of Wuhuan, which in the 4th century, was another term for "miscellaneous hu" or "zahu" (雜胡). It was not until Helian Bobo came to power that they fully affirm their Xiongnu lineage in a bid for legitimacy by claiming descent from the ancient Xia dynasty.

Weinan (Chinese: 渭南; pinyin: Wèinán) is a prefecture-level city in east-central Shaanxi province, northwest China. The city lies on the lower section of the Wei River confluence into the Yellow River, about 60 km (37 mi) east of the provincial capital Xi'an, and borders the provinces of Shanxi and Henan to the east.

The name "Weinan", literally meaning "south of the Wei River", describes the location of the city's urban districts being mostly south of the Wei River, although majority of its metropolitan area actually lies on the north side of the river.

Northern Shaanxi or Shaanbei (陕北) is the northern portion of China's Shaanxi province. More specifically, it refers to the region north of the Huanglong Mountain and the Meridian Ridge (the so-called "Guanzhong north mountains") within the province. Being both a geographic area as well as a cultural area, it makes up the southeastern portion of the Ordos Basin and forms the northern part of the Loess Plateau. The region includes two prefecture-level cities: Yulin, which is known for the Ming Great Wall traversing through its northern part; and Yan'an, which is known for being the birthplace of the Chinese Communist Revolution.

The Upheaval of the Five Barbarians also translated as the Uprising, Rebellion or the Revolt of the Five Barbarians (simplified Chinese: 五胡乱华; traditional Chinese: 五胡亂華; lit. 'Five foreign tribes disrupting China') is a Chinese expression used to refer to a chaotic period of warfare from 304 to 316 during the fall of the Western Jin dynasty. Overlapping with the War of the Eight Princes, these conflicts which involved non-Han groups living within China eventually drove the Jin imperial court out of the northern and southwestern China.

The "Five Barbarians" were the Xiongnu, Jie, Qiang, Di and Xianbei, many of whom had resettled within China during the preceding centuries. Despite the period's name, many Han Chinese and other tribal people like the Wuhuan were also involved, wavering their support between Jin and the separatist regimes. Years of poor administration and civil wars between the ruling princes left the empire open to its disaffected and opportunistic subjects. Ethnic tensions in the Guanzhong region between the Han and the tribes, primarily the Qiang and Di, led to major revolts which resulted in an exodus of refugees into southwestern China. Efforts to force them back to Guanzhong were met with resistance and culminated in the rebellion of the Ba-Di refugee, Li Te in 301.

Hangu Pass or Hanguguan was a fortified gateway that commanded the strategic mountain pass between the Yellow River and Qinling Mountains, forming the main choke point on the only land corridor between the Central Plain and the Guanzhong region. The pass restricted access into the lower Wei River valleys, where the heartland of the state of Qin and the unified Qin dynasty were located, as well as the subsequent dynasties of Han, Sui and Tang.

The Hangu Pass lies on the south (right) bank of the Yellow River, 60 km (37 mi) downstream of its eastward bend out of the Ordos Loop. It was built by the state of Qin in 330 BC and had been the site of many sieges and field battles during the Warring States period and early imperial eras. Due to terrain changes from bank erosions and alluvial deposition of the Yellow River over the centuries, the Hangu Pass eventually fell to ruins after losing its defensive values to the newer Tong Pass to its west, which was built near the mouth of the Wei River in 196 AD by the warlord Cao Cao.

Qin, known in historiography as the Later Qin (simplified Chinese: 后秦; traditional Chinese: 後秦; pinyin: Hòuqín; 384–417) or Yao Qin (姚秦), was a dynastic state of China ruled by the Yao clan of Qiang ethnicity during the Sixteen Kingdoms period in northern China. As the only Qiang-led state among the Sixteen Kingdoms, it was most known for its propagation of Buddhism under its second ruler, Yao Xing, who sponsored the Madhyamakin monk, Kumārajīva to translate Sanskrit Buddhist text into Chinese.

All rulers of the Later Qin declared themselves emperors, but for a substantial part of Yao Xing's reign, he used the title Heavenly King. Historiographers gave the state the prefix of "Later" to distinguish it with the Former Qin and Western Qin as it was founded during the Former Qin's collapse after the Battle of Fei River and went on to conquer the Former Qin's power base in the Guanzhong. With Chang'an as its capital, the Later Qin also controlled Henan and vassalised the Western Qin, the four Liangs (Later, Southern, Northern and Western), Southern Yan, Qiao Shu, Chouchi and various tribes of the Ordos region.

Yan, known in historiography as the Western Yan (Chinese: 西燕; pinyin: Xī Yān; 384–394) was a dynastic state of China ruled by the Xianbei ethnicity. The dynasty existed during the era of Sixteen Kingdoms, but it is not counted among the 16. It was founded by Murong Hong in 384 in the aftermath of the Former Qin's defeat by the Eastern Jin in the Battle of Fei River, with the stated intent of permitting the Xianbei, whom the Former Qin's emperor Fu Jiān had relocated to Former Qin's capital region after destroying the Former Yan in 370. It initially also was intended to rescue the last Former Yan emperor Murong Wei, until he was executed by Fu Jiān in 385. It was a state that was characterized by extreme political instability and internal fighting, as all seven of its rulers (during a short span of 10 years) died of unnatural causes. After eviscerating the Former Qin, the people of the state abandoned the Guanzhong region and headed east back toward their homeland, but eventually settled down in modern Shanxi. It was destroyed in 394 as Later Yan's emperor Murong Chui wanted to reunite the people formerly of Yan and conquered it.

Some rulers of the Western Yan declared themselves emperors while some declared themselves wang (translatable as either "king" or "prince").

Zhang Han (died c. June or July 205 BC) was a Chinese military general of the Qin dynasty. Between 209 and 208 BC, when uprisings against the Qin dynasty broke out, Zhang Han, along with Sima Xin and Dong Yi, led Qin forces into battle against the various rebel groups and defeated some of them. However, they lost to rebel forces led by Xiang Yu in 207 BC at the Battle of Julu and were forced to surrender. After the rebels overthrew the Qin dynasty in 206 BC, China was divided into the Eighteen Kingdoms and the three surrendered Qin generals were made kings – Zhang Han as the King of Yong, Sima Xin as the King of Sai, and Dong Yi as the King of Di. Their three kingdoms were collectively known as the Three Qins since they occupied the Guanzhong region, the heartland of the Qin state during the Warring States period. In 205 BC, Liu Bang, the King of Han, invaded Zhang Han's kingdom and defeated Zhang Han in battle. Zhang Han committed suicide after his defeat.

The Predynastic Zhou or Proto-Zhou (/dʒoʊ/; Chinese: 先周) refers to the ancient Chinese state ruled by the Ji clan that existed in the Guanzhong region (modern central Shaanxi province) during the Shang dynasty, before its rebellion and subsequent conquest of the Shang in 1046-1045 BC led to the establishment of the Zhou dynasty. According to histories, predynastic Zhou rose as a western frontier vassal state of the Shang, acting as its ally against the Xirong barbarians until their influence surpassed that of the Shang dynasty.

Records about predynastic Zhou came from two sources. The Shang dynasty kept records about Zhou in oracle bones. The texts about Zhou inscribed by the Shang court are mainly those from the reign of Wu Ding and the last Shang monarchs. After the fall of Shang, the Ji clan established the Zhou dynasty and started their own narrative about previous generations. The Book of Documents and the Bamboo Annals are two major historical sources. Later, Sima Qian wrote about the country using those texts as reference.