Before it is referred to as the Qin Dynasty, the Ying were the rulers of the Qin .
According to Sima Qian, the house of Qin traced its origin to Emperor Zhuanxu . One of their ancestors, Dafei received from Emperor Shun the surname Ying. Another ancestor, Feizi served King Xiao of Zhou as the royal horse trainer, was rewarded with a fief in Quanqiu ; the Qin state grew out from this area, and the Qin name itself is believed to have originated, in part,there.
Qin Shi Huangdi
Qin Shi Huangdi imposed the Qin state's centralized, non-hereditary aristocratic system on his new empire in place of the Zhou's one. The Qin Empire relied on the philosophy of . Centralization, achieved by ruthless methods, was focused on standardizing legal codes and bureaucratic procedures, the forms of writing and coinage, and the pattern of thought and scholarship. The seal script s from the former state of Qin became the standard for the entire empire. The length of the wheel axle was also unified and expressways standardized to ease transportation throughout the country. To silence criticism of imperial rule, the emperor banished or put to death many dissenting Confucian scholars and confiscated and .
To prevent future uprisings, Qin Shi Huangdi ordered the confiscation of weapons and stored them in the capital. In order to prevent the resurgence of feudal lords, he also destroyed the walls and fortifications that had separated the previous six states. A national conscription was devised: every male between the ages of seventeen and sixty years was obliged to serve one year in the army. Qin aggrandizement was aided by frequent military expeditions pushing forward the frontiers in the north and south. To fend off a barbarian intrusion , the fortification walls built by the various warring states were connected to make a wall; this is usually recognized as the first Great Wall of China, although the present, 4,856- kilometer-long Great Wall of China was largely built or re-built during the Ming Dynasty. A number of public works projects, including canals and bridges, were also undertaken to consolidate and strengthen imperial rule. A lavish tomb for the emperor, complete with a Terracotta Army, was built near the capital Xianyang, a city half an hour from modern Xi'an. These activities required enormous levies of manpower and resources, not to mention repressive measures.
Qin Shi Huangdi's behavior reportedly became increasingly erratic in the later years of his rule. This may have been the result of drinking solutions containing mercury as well as other deadly compounds. Ironically, Shi Huangdi ingested the mixtures in an increasingly desperate search for an elixir that would prolong his life. It has often been speculated that this was at least partially responsible for many of his later acts such as building the .
Campaigns against Xiongnu
When Emperor Qin Shi Huangdi had succeeded in his conquest of all the six warring states in China he began to concentrate its aggression against the nomadic ethnic Xiongnu which had grown into a powerful invading force in the north and started expanding both east and west. Qin Shi Huang, the first emperor of the Qin Dynasty, sent a 300,000-strong army headed by General Meng Tian to drive the Xiongnu northward for 350 km and built the Great Wall to guard against its invasion.
Burning of intellectual books and Confucian burying
Qin Shi Huangdi had allowed the burning of intellectual books and burying Confucians alive when Li Si , his prime minister, had won favor over Chunyu Yue on the matter of commandary-county system, proposed book burning. In 213 BC, on Li Si's urging, Qin Shi Huangdi outlawed all other schools of thought except for Legalism, and he ordered book burning. 346 to 460 Confucians local to Qin capital were buried alive at one time. When Qin Shi Huangdi's elder son, Prince Fusu, encountered the rows of Confucians who were on the way to the burial ground, he went straight to Qin Shi Huangdi pleading for amnesty on behalf of the Confucians. Qin Shi Huangdi rebutted Fusu and further sent his elder son to Shangjun Commandary on the northern border to be with General Meng Tian. Qin Shi Huangdi then played a trick to have various prefectures send over about 700 more Confucians and scholars. All 700 Confucians were stoned to death in a valley, a place later named "valley of Confucian killing".
During the last trip with his youngest son in 210 BC, Qin Shi Huang died suddenly at Shaqiu prefecture. Huhai, under the advice of two high officials, the Imperial Secretariat Li Si and the chief eunuch Zhao Gao, forged and altered Emperor's will. The faked decree ordered Qin Shi Huang's first son, the heir Fusu to commit suicide, instead naming Huhai as the next emperor. The decree also stripped the command of troops from Marshal Meng Tian — a faithful supporter of Fusu — and sentenced Meng's family to death. ''Zhao Gao'' step by step seized the power of Huhai, effectively making Huhai a puppet emperor. Thus beginning the Qin dynasty decline.
Out of concern for the security of his throne, Huhai killed all his brothers and sisters. At the end, he was killed by Zhao Gao. Thus Qin Shi Huang, the First Emperor, has no known descendants. The Second Emperor, Huhai, also has no known descendants.
Within three years of Qin Shi Huangdi's death, widespread revolts by peasants, prisoners, soldiers, and descendants of the nobles of the Six Warring States sprang up all over China. Chen Sheng and Wu Guang, two in a group of about 900 soldiers assigned to defend against the Xiongnu , became the leaders of the first revolution by commoners.
Huhai lived to see the Battle of Julu, the major defeat of the Qin army in the hands of the rebels, which marked the end of the Qin Dynasty.
In the beginning of October 207 BC, Zhao Gao forced Huhai to commit suicide and replaced him with Fusu's son, Ziying . Note that the title of Ziying was "king of Qin" to reflect the fact that Qin no longer controlled the whole of China. The Chu-Han contention ensued. Ziying soon killed Zhao Gao and surrendered to Liu Bang in the beginning of December 207 BC. But Liu Bang was forced to hand over Xianyang and Ziying to Xiang Yu. Xiang Yu then killed Ziying and burned down the palace in the end of January 206 BC. It is said the fire lasted two months before the inferno died down. A recent archeology survey of the palace ruin determined it to be roughly the size of Manhattan island of New York City. The palace is supported with thousands of pillars made from prehistoric lumbers growing to up to 115 meters high. One single pillar requires a team of a thousand workers a life time to harvest. Due to the weight and scale of each lumber, cutting the lumber can take weeks if not months, transporting from the prehistoric forest to the lumber mill requires certain weather so the river can be flooded to even move the massive lumber down river. The captain of each team is rewarded with imperial rank, their goal in life is to acquire one of these prehistoric lumber for the construction of the palace. It is said each pillar sacrificed the lives of a hundred men. Xiang Yu's controversial action sets the stage for the legendary battles between Xiang Yu, the warrior king and Liu Bang, the people's king. The Qin dynasty came to an end, three years after the death of Qin Shi Huang, and less than twenty years after it was founded.
Although the Qin Dynasty was short-lived, its legalist rule had a deep impact on later dynasties in China. The imperial system initiated during the Qin dynasty set a pattern that was developed over the next two millennia.
Sovereigns of Qin Dynasty
Note: King Zhaoxiang of Qin had already been ruling Qin for 51 years when Qin annihilated the Zhou Dynasty; however the other six warring states were still independent regimes. Historiographers thus used the next year as the official continuation from Zhou Dynasty.
Qin Shi Huang was the first Chinese sovereign to proclaim himself "Emperor", after reunifying China in 221 BC. That year is therefore usually taken as the start of the "Qin Dynasty".