Xia (Sixteen Kingdoms)

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 the height of their power, 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 classed as a group of Wuhuan, which had become a broad ethnic label in the 4th century. 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.

The rulers of Xia came from the Tiefu tribe, who descended from the Southern Xiongnu Wise Prince of the Left, Qubei. Qubei was a member of the imperial Luandi clan as the uncle of the last chanyu, Huchuquan, although a later and more dubious account alleged that he was the descendant of a Han dynasty prince-turned-Xiongnu noble, Liu Jinbo instead. In 196, Qubei assisted the warlord, Cao Cao in escorting Emperor Xian of Han to Xuchang, and in 216, Cao Cao appointed him to supervise the Five Divisions of the Southern Xiongnu in modern-day Shanxi. As the Xiongnu imperial family claimed descent from the Han dynasty through their heqin marriages with Han princesses, Qubei's family adopted "Liu" (劉) as their surname.

Qubei's family entered a decline following his death. His son, Liu Meng rebelled against the Western Jin but received little support and was ultimately killed. His brother, Liu Gaoshengyuan inherited his followers, and Gaoshengyuan's son, Liu Hu later succeeded him to the chieftaincy. Liu Hu further adopted the clan name of "Tiefu", meaning a person with a Xiongnu father and Xianbei mother, which suggests that his tribe had intermingled with the Xianbei. Additionally, the Tiefu were also referred to as Wuhuan, which by Liu Hu's time, had become a broad label for Xiongnu tribes that mixed with the Donghu people (Wuhuan and Xianbei).

In 310, Liu Hu led his people to another revolt, but the Jin, with aid from the Tuoba-Xianbei tribe, drove him west to Shuofang Commandery in the Ordos Plateau. His distant cousin, the Emperor of Han (Zhao), Liu Cong, acknowledged him as kin and gave him the title of Duke of Loufan. At the time, the Ordos had largely been abandoned by the Chinese dynasties since the fall of Han and became a dwelling space for a myriad of nomadic tribes. The Tiefu settled in their new home and grew into a influential clan in the region. However, they were constantly threatened by the Tuoba in the east, who were rewarded the princely fied of Dai by the Jin for their effort in quelling Liu Hu's rebellion. The Tiefu were often defeated in battle, which forced them to vacillate between submitting to the Dai and becoming vassals to the dynasties of the Central and Guanzhong Plains (Han-Zhao, Later Zhao and Former Qin).

The Tiefu and Tuoba conflict was particularly intense during the chieftaincy of Liu Weichen. In 376, he finally convinced his overlord, the Former Qin, to carry out a major campaign on the Dai. With Liu Weichen acting as their guide, the Qin conquered Dai, thereby unifying all of northern China, and rewarded him with the western half of the former Tuoba territory. During the collapse of Former Qin after the Battle of Fei River in 383, Liu Weichen re-asserted his autonomy over the Ordos from Shuofang and assembled a powerful force under him. In 391–392, he set his sights on subjugating the Tuoba tribe, who had reestablished their state as the Northern Wei. However, the campaign ended in disaster, and Liu Weichen was killed along with most of his tribe.

Liu Weichen's son, Liu Bobo, survived the fall of his tribe. He initially fled south to the Xuegan tribe, who then sent him to the Poduoluo. The chieftain of the Poduoluo, Moyigan, took Liu under his wing and gave him a daughter to marry. As the Qiang-led Later Qin dynasty closed in on unifying the Guanzhong region, the Qin began accepting submissions from tribes in the Ordos to form a buffer zone along their northern frontier. The Poduoluo was one these tribes, and in the early reign of Yao Xing, Liu Bobo was introduced to Yao, who sent him back to Shuofang and entrusted him as a major border commander.

During this period, the Northern Wei was rapidly rising in power and continued to ravage the Ordos tribes with their raids, leading to general unrest on the frontier. In retaliation, Yao Xing led an eastern expedition against the Wei, but suffered a decisive defeat at the Battle of Chaibi in 402. From then on, the Qin avoided further military engagements with the Wei and sought to mend their relationship through appeasements. In 407, Liu Bobo, angered by peace talks between Yao Xing and the Tuoba, raised an army in rebellion against the Qin, killing his father-in-law, Moyigan in an ambush and absorbing his tribe.