公元前206年，刘邦建立了强大的汉王朝。汉代的农业、手工业、商业都有了极大发展，人口达到5000万。汉武帝刘彻在位期间（公元前140—前87年）是汉王朝最为强盛的时期，他使中央政权实际控制的地方从中原扩展到了西域（今新疆及中亚一带）。他派使臣张骞两次出使西域，打开了从长安（今陕西西安）经新疆、中亚直抵地中海东岸的道路，被称为“丝绸之路”，中国绚丽的丝织品经此源源西运。随着东西交往的密切，佛教也于公元一世纪时传入中国。公元105年，官员蔡伦总结了民间造纸的经验，发明了造纸术，使人类的书写材料发生了根本性变化。
The Han Dynasty (simplified Chinese: 汉朝; traditional Chinese: 漢朝; pinyin: Hàn Cháo; Wade–Giles: Han Ch'ao; IPA: [xân tʂʰɑ̌ʊ̯]; 206 BCE – 220 CE) was the second imperial dynasty of China, preceded by the Qin Dynasty (221–206 BCE) and succeeded by the Three Kingdoms (220–265 CE). It was founded by the peasant rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han. It was briefly interrupted by the Xin Dynasty (9–23 CE) of the former regent Wang Mang. This interregnum separates the Han into two periods: the Western Han (206 BCE – 9 CE) and Eastern Han (25–220 CE). Spanning over four centuries, the period of the Han Dynasty is considered a golden age in Chinese history. To this day, China's majority ethnic group refers to itself as the "Han people".
The Han Empire was divided into areas directly controlled by the central government, known as commanderies, and a number of semi-autonomous kingdoms. These kingdoms gradually lost all vestiges of their independence, particularly following the Rebellion of the Seven States. The Xiongnu, a nomadic confederation which dominated the eastern Eurasian Steppe, defeated the Han army in battle in 200 BCE. Following the defeat, a political marriage alliance was negotiated in which the Han became the de facto inferior partner. When, despite the treaty, the Xiongnu continued to raid Han borders, Emperor Wu of Han (r. 141–87 BCE) launched several military campaigns against them. The ultimate Han victory in these wars eventually forced the Xiongnu to accept vassal status as Han tributaries. These campaigns expanded Han sovereignty into the Tarim Basin of Central Asia and helped establish the vast trade network known as the Silk Road, which reached as far as the Mediterranean world. Han forces managed to divide the Xiongnu into two competing nations, the Southern and Northern Xiongnu, and forced the Northern Xiongnu across the Ili River. Despite these victories, the territories north of Han's borders were quickly overrun by the nomadic Xianbei Confederation.
After 92 CE, the palace eunuchs increasingly involved themselves in court politics, engaging in violent power struggles between the various consort clans of the empresses and empress dowagers, causing the Han's ultimate downfall. Imperial authority was also seriously challenged by large Daoist religious societies which instigated the Yellow Turban Rebellion and the Five Pecks of Rice Rebellion. Following the death of Emperor Ling (r. 168–189 CE), the palace eunuchs suffered wholesale massacre by military officers, allowing members of the aristocracy and military governors to become warlords and divide the empire. When Cao Pi, King of Wei, usurped the throne from Emperor Xian, the Han Dynasty ceased to exist.
The Han Dynasty was an age of economic prosperity and saw a significant growth of the money economy first established during the Zhou Dynasty (c. 1050–256 BCE). The coinage issued by the central government mint in 119 BCE remained the standard coinage of China until the Tang Dynasty (618–907 CE). To pay for its military campaigns and the settlement of newly conquered frontier territories, the government nationalized the private salt and iron industries in 117 BCE. These government monopolies were repealed during the Eastern Han period, and the lost revenue was recouped through heavily taxing private entrepreneurs. The emperor was at the pinnacle of Han society. He presided over the Han government but shared power with both the nobility and appointed ministers who came largely from the scholarly gentry class. From the reign of Emperor Wu onward, the Chinese court officially sponsored Confucianism in education and court politics, synthesized with the cosmology of later scholars such as Dong Zhongshu. This policy endured until the fall of the Qing Dynasty in 1911 CE. Science and technology during the Han period saw significant advances, including papermaking, the nautical steering rudder, the use of negative numbers in mathematics, the raised-relief map, the hydraulic-powered armillary sphere for astronomy, and a seismometer employing an inverted pendulum.
