Xiongnu in the context of "Heqin"

Sima Qian (c. 145 BC – c. 86 BC) was a Chinese historian during the early Han dynasty. He is considered the father of Chinese historiography for the Shiji (sometimes translated into English as Records of the Grand Historian), a general history of China covering more than two thousand years from the rise of the legendary Yellow Emperor and formation of the first Chinese polity to the reign of Emperor Wu of Han, during which Sima wrote. As the first universal history of the world as it was known to the ancient Chinese, the Shiji served as a model for official histories for subsequent dynasties across the Sinosphere until the 20th century.

Sima Qian's father, Sima Tan, first conceived of the ambitious project of writing a complete history of China, but had completed only some preparatory sketches at the time of his death. After inheriting his father's position as court historian in the imperial court, he was determined to fulfill his father's dying wish of composing and putting together this epic work of history. However, in 99 BC, he would fall victim to the Li Ling affair for speaking out in defense of the general, who was blamed for an unsuccessful campaign against the Xiongnu. Given the choice of being executed or castrated, he chose the latter in order to finish his historical work. Although he is universally remembered for the Records, surviving works indicate that he was also a gifted poet and prose writer, and he was instrumental in the creation of the Taichu calendar, which was officially promulgated in 104 BC.

A barbarian is a person or tribe of people that is perceived to be primitive, savage, and warlike. A "barbarian" may also be an individual reference to an aggressive, brutal, cruel, and insensitive person, particularly one who is also dim-witted, while cultures, customs and practices adopted by peoples and countries perceived to be primitive may be referred to as "barbaric".

The term originates from the Ancient Greek: βάρβαρος (barbaros; pl. βάρβαροι barbaroi). In ancient Greece, the Greeks used the term not only for those who did not speak Greek and follow classical Greek customs, but also for Greek populations on the fringe of the Greek world with peculiar dialects. In ancient Rome, the Romans adapted and applied the term to tribal non-Romans such as the Xiongnu, Mongols, Germans, Celts, Iberians, Helvetii, Thracians, Illyrians, and Sarmatians. In the early modern period and sometimes later, the Byzantine Greeks used it for the Turks in a clearly pejorative manner.

Mongolia is a landlocked country in East Asia. Bordered by Russia to the north and China to the south and southeast, it covers an area of 1,564,116 square kilometres (603,909 square miles), making it the 18th-largest country in the world and the second largest landlocked country after Kazakhstan, as well as the largest landlocked country that does not border an inland sea. With a population of 3.5 million, it is the world's most sparsely populated sovereign state. The country constitutes a significant portion of the Mongolian Plateau, and its natural environment is characterized by grassy steppe, mountains to the north and west, and the Gobi Desert to the south. Ulaanbaatar, the capital and largest city, is home to roughly half of the country's population.

The territory of modern-day Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the First Turkic Khaganate, the Second Turkic Khaganate, the Uyghur Khaganate and others. In 1206, Genghis Khan founded the Mongol Empire, which became the largest contiguous land empire in history. His grandson Kublai Khan conquered China proper and established the Yuan dynasty. After the collapse of the Yuan, the Mongols retreated to Mongolia and resumed their earlier pattern of factional conflict, except during the era of Dayan Khan and Tumen Zasagt Khan.

Various nomadic empires, including the Xiongnu (3rd century BC–1st century AD), the Xianbei state (c. AD 93–234), the Rouran Khaganate (330–555), the First (552–603) and Second Turkic Khaganates (682–744) and others, ruled the area of present-day Mongolia. The Khitan people, who used a para-Mongolic language, founded an empire known as the Liao dynasty (916–1125), and ruled Mongolia and portions of North China, northern Korea, and the present-day Russian Far East.

In 1206, Genghis Khan was able to unite the Mongol tribes, forging them into a fighting force which went on to establish the largest contiguous empire in world history, the Mongol Empire (1206–1368). After the fragmentation of the Mongol Empire, Mongolia came to be ruled by the Yuan dynasty (1271–1368) based in Khanbaliq (modern Beijing) and administered as part of the Lingbei Province. Buddhism in Mongolia began with the Yuan emperors' conversion to and dissemination of Tibetan Buddhism.

The Eurasian Steppe, also called the Great Steppe or The Steppes, is the vast steppe ecoregion of Eurasia in the temperate grasslands, savannas and shrublands biome. It stretches through Manchuria, Mongolia, Xinjiang, Kazakhstan, Siberia, European Russia, Ukraine, Moldova, Romania, Bulgaria, Hungary and Slovakia.

Since the Paleolithic age, the Steppe Route has been the main overland route between Eastern Europe, North Asia, Central Asia and East Asia economically, politically, and culturally. The Steppe route is a predecessor not only of the Silk Road, which developed during antiquity and the Middle Ages, but also of the Eurasian Land Bridge in the modern era. It has been home to nomadic empires and many large tribal confederations and ancient states throughout history, such as the Xiongnu, Scythia, Cimmeria, Sarmatia, Hunnic Empire, Sogdia, Xianbei, Mongol Empire, Magyar tribes, and Göktürk Khaganate.

Nomadic empires, sometimes also called steppe empires, Central or Inner Asian empires, were the empires erected by the bow-wielding, horse-riding, nomadic people in the Eurasian Steppe, from classical antiquity (Scythia) to the early modern era (Dzungars). They are the most prominent example of non-sedentary polities.

Some nomadic empires consolidated by establishing a capital city inside a conquered sedentary state and then exploiting the existing bureaucrats and commercial resources of that non-nomadic society. In such a scenario, the originally nomadic dynasty may become culturally assimilated to the culture of the occupied nation before it is ultimately overthrown. Ibn Khaldun (1332–1406) described a similar cycle on a smaller scale in 1377 in his Asabiyyah theory.

Emperor Wu of Han (156 – 29 March 87 BC), personal name Liu Che and courtesy name Tong, was the seventh emperor of the Han dynasty from 141 to 87 BC. His reign lasted 54 years – a record not broken until the reign of the Kangxi Emperor more than 1,800 years later – and remains the record for ethnic Han emperors. His reign resulted in a vast expansion of geopolitical influence for the Chinese civilization, and the development of a strong centralized state via governmental policies, economical reorganization and promotion of a hybrid Legalist–Confucian doctrine. In the field of historical social and cultural studies, Emperor Wu is known for his religious innovations and patronage of the poetic and musical arts, including the development of the Imperial Music Bureau into a prestigious entity. It was also during his reign that cultural contact with western Eurasia was greatly increased, directly and indirectly.

During his reign, Emperor Wu led the Han dynasty through its greatest territorial expansion. At its height, the Empire's borders spanned from the Fergana Valley in the west, to northern Korea in the east, and to northern Vietnam in the south. Emperor Wu successfully repelled the nomadic Xiongnu from systematically raiding northern China, and dispatched his envoy Zhang Qian into the Western Regions in 139 BC to seek an alliance with the Greater Yuezhi and Kangju, which resulted in further diplomatic missions to Central Asia. Although historical records do not describe him as being aware of Buddhism, emphasizing rather his interest in shamanism, the cultural exchanges that occurred as a consequence of these embassies suggest that he received Buddhist statues from Central Asia, as depicted in the murals found in the Mogao Caves.

Li Ling (Chinese: 李陵; pinyin: Lǐ Líng, died 74 BC), courtesy name Shaoqing (Chinese: 少卿; pinyin: Shǎoqīng), was a Chinese military general of the Western Han dynasty who served during the reign of Emperor Wu. He later defected to the Xiongnu after being defeated in an expedition in 99 BC.

Qin Shi Huang (Chinese: 秦始皇, Qín Shǐ Huáng, pronunciation; February 259 – 12 July 210 BC) was the founder of the Qin dynasty and the first emperor of China. Rather than maintain the title of "king" (wáng 王) borne by the previous Shang and Zhou rulers, he assumed the invented title of "emperor" (huángdì 皇帝), which would see continuous use by monarchs in China for the next two millennia.

Born in Handan, the capital of Zhao, as Ying Zheng (嬴政) or Zhao Zheng (趙政), his parents were King Zhuangxiang of Qin and Lady Zhao. The wealthy merchant Lü Buwei assisted him in succeeding his father as the king of Qin, after which he became King Zheng of Qin (秦王政). By 221 BC, he had conquered all the other warring states and unified all of China, and he ascended the throne as China's first emperor. During his reign, his generals greatly expanded the size of the Chinese state: campaigns south of Chu permanently added the Yue lands of Hunan and Guangdong to the Sinosphere, and campaigns in Inner Asia conquered the Ordos Plateau from the nomadic Xiongnu, although the Xiongnu later rallied under Modu Chanyu.