Spring and Autumn Period

In the 8th century BC, power became decentralized during the Spring and Autumn Period (春秋時代), named after the influential Spring and Autumn Annals . In this period, local military leaders used by the Zhou began to assert their power and vie for hegemony. The situation was aggravated by the invasion of other peoples from the northwest, such as the Qin, forcing the Zhou to move their capital east to Luoyang. This marks the second large phase of the Zhou dynasty: the Eastern Zhou. In each of the hundreds of states that eventually arose, local strongmen held most of the political power and continued their subservience to the Zhou kings in name only. Local leaders for instance started using royal titles for themselves. The Hundred Schools of Thought (諸子百家/诸子百家) of Chinese philosophy blossomed during this period, and such influential intellectual movements as Confucianism (儒家), Taoism (道家), Legalism (法家) and Mohism (墨家) were founded, partly in response to the changing political world. The Spring and Autumn Period is marked by a falling apart of the central Zhou power. China now consists of hundreds of states, some only as large as a village with a fort.

Warring States Period

After further political consolidation, seven prominent states remained by the end of 5th century BC, and the years in which these few states battled each other are known as the Warring States Period. Though there remained a nominal Zhou king until 256 BC, he was largely a figurehead and held little real power.

As neighboring territories of these warring states, including areas of modern Sichuan and Liaoning, were annexed, they were governed under the new local administrative system of commandery and prefecture (郡縣/郡县). This system had been in use since the Spring and Autumn Period and parts can still be seen in the modern system of Sheng & Xian (province and county, 省縣/省县). The final expansion in this period began during the reign of Ying Zheng (嬴政), the king of Qin. His unification of the other six powers, and further annexations in the modern regions of Zhejiang , Fujian , Guangdong and Guangxi in 214 BC enabled him to proclaim himself the First Emperor (Qin Shi Huangdi, 秦始皇帝).

China Imperial Era - (221 BC - 280 AD)

Qin Dynasty (221 BC - 206 BC)

Historians often refer to the period from Qin Dynasty to the end of Qing Dynasty as Imperial China. Though the unified reign of the Qin (秦) Emperor lasted only 12 years, he managed to subdue great parts of what constitutes the core of the Han Chinese homeland and to unite them under a tightly centralized Legalist government seated at Xianyang (咸陽/咸阳) (close to modern Xi'an).

The doctrine of legalism that guided the Qin emphasized strict adherence to a legal code and the absolute power of the emperor. This philosophy of Legalism, while effective for expanding the empire in a military fashion, proved unworkable for governing it in peace time. The Qin presided over the brutal silencing of political opposition, including the event known as the burning and burying of scholars. This would be the impetus behind the later Han Synthesis incorporating the more moderate schools of political governance.

The Qin Dynasty is well known for beginning the Great Wall of China , which was later augmented and enhanced during the Ming Dynasty (明朝). The other major contributions of the Qin include the concept of a centralized government, the unification of the legal code, written language, measurement, and currency of China after the tribulations of the Spring and Autumn and Warring States Periods. Even something as basic as the length of axles for carts had to be made uniform to ensure a viable trading system throughout the empire.

Han Dynasty (206 BC - 220 AD)

The Han Dynasty emerged in 206 BC. It was the first dynasty to embrace the philosophy of Confucianism, which became the ideological underpinning of all regimes until the end of imperial China. Under the Han Dynasty, China made great advances in many areas of the arts and sciences.

Emperor Wu (Han Wudi 汉武帝) consolidated and extended the Chinese empire by pushing back the Xiongnu (sometimes identified with the Huns) into the steppes of modern Inner Mongolia , wresting from them the modern areas of Gansu , Ningxia and Qinghai. This enabled the first opening of trading connections between China and the West, the Silk Road.

Nevertheless, land acquisitions by elite families gradually drained the tax base. In AD 9 , the usurper Wang Mang (王莽) founded the short-lived Xin ("New") Dynasty (新朝) and started an extensive program of land and other economic reforms. These programs, however, were never supported by the land-holding families, for they favored the peasants. The instability brought about chaos and uprisings.

Emperor Guangwu (光武帝) reinstated the Han Dynasty with the support of land-holding and merchant families at Luoyang , east of Xi'an . This new era would be termed the Eastern Han Dynasty. Han power declined again amidst land acquisitions, invasions, and feuding between consort clans and eunuchs. The Yellow Turban Rebellion (黄巾之乱) broke out in 184, ushering in an era of warlords . In the ensuing turmoil, three states tried to gain predominance in the Period of the Three Kingdoms. This time period has been greatly romanticized in works such as Romance of the Three Kingdoms

The Three Kingdoms period (220 AD - 280 AD) (三国) is a period in the history of China, part of an era of disunity called the Six Dynasties following immediately the loss power of the Han Dynasty emperors. In a strict academic sense it refers to the period between the foundation of the Wei in 220 and the conquest of the Wu by the Jin Dynasty in 280. However, many Chinese historians and laymen extend the starting point of this period back to the uprising of the Yellow Turbans in 184.

The three kingdoms were Wèi (魏), Shǔ (蜀), and Wú (吴). To help further distinguish these states from other historical Chinese states of the same name, historians add a relevant character: Wei is also known as Cáo Wèi (曹魏), Shu is also known as Shǔ Hàn (蜀汉), and Wu is also known as Dōng Wú or Eastern Wu (东吴). The term Three Kingdoms itself is somewhat a mistranslation, since each state was eventually headed by an emperor who claimed legitimate succession from the Han Dynasty, not by kings. Nevertheless the term has become standard among sinologists.

The earlier, "unofficial" part of the period, from 190 to 220, was marked by chaotic infighting between warlords in various parts of China. The middle part of the period, from 220 and 263, was marked by a more militarily stable arrangement between three rival states, Cao Wei, Shu Han, and Eastern Wu. The later part of this period was marked by the collapse of the tripartite situation: first the destruction of Shu by Wei ( 263 ), then the overthrow of Wei by the Jin Dynasty ( 265 ), and the destruction of Wu by Jin (280 ).

Although relatively short, this historical period has been greatly romanticised in the cultures of China, Japan, Korea, and Vietnam. It has been celebrated and popularized in operas, folk stories, novels and in more recent times, films, television serials, and video games. The best known of these is undoubtedly the Romance of the Three Kingdoms, a fictional account of the period which draws heavily on history. The authoritative historical record of the era is Chen Shou's Sanguo Zhi, along with Pei Songzhi's later annotations of the text.

The Three Kingdoms period is one of the bloodiest in Chinese history. A population census in late Eastern Han Dynasty reported a population of approximately 50 million, while a population census in early Western Jin Dynasty (after Jin re-unified China) reported a population of approximately 16 million. Even after taking into account possible inaccuracies of these census reports, a large percentage of the population was wiped out during the constant wars waged during this period. China Imperial Era - (265 AD - 618 AD)