The Qin dynasty (//; Chinese: 秦朝; pinyin: Qín Cháo; Wade–Giles: Ch'in2 Ch'ao2) was the first dynasty of Imperial China, lasting from 221 to 206 BC. Named for its heartland in Qin state (modern Gansu and Shaanxi), the dynasty was founded by Qin Shi Huang, the First Emperor of Qin. The strength of the Qin state was greatly increased by the Legalist reforms of Shang Yang in the fourth century BC, during the Warring States period. In the mid and late third century BC, the Qin state carried out a series of swift conquests, first ending the powerless Zhou dynasty, and eventually conquering the other six of the Seven Warring States. Its 15 years was the shortest major dynasty in Chinese history, consisting of only two emperors, but inaugurated an imperial system that lasted, with interruption and adaptation, until 1912.
The Qin sought to create a state unified by structured political power and a large military supported by a stable economy. The central government moved to undercut aristocrats and landowners to gain direct administrative control over the peasantry, who comprised the overwhelming majority of the population and labour force. This allowed ambitious projects involving three hundred thousand peasants and convicts, such as connecting walls along the northern border, eventually developing into the Great Wall of China.
The Qin introduced a range of reforms such as standardized currency, weights, measures, and a uniform system of writing, which aimed to unify the state and promote commerce. Additionally, its military used the most recent weaponry, transportation, and tactics, though the government was heavy-handedly bureaucratic. Han dynasty Confucians portrayed the dynasty as a monolithic tyranny, notably citing a purge known as the burning of books and burying of scholars although some modern scholars dispute the veracity of these accounts.
When the first emperor died in 210 BC, two of his advisers placed an heir on the throne in an attempt to influence and control the administration of the dynasty. These advisors squabbled among themselves, resulting in both of their deaths and that of the second Qin Emperor. Popular revolt broke out and the weakened empire soon fell to a Chu general, Xiang Yu, who was proclaimed Hegemon-King of Western Chu, and Liu Bang, who later founded the Han dynasty. Despite its short reign, the dynasty greatly influenced the future of China, particularly the Han, and its name is thought to be the origin of the European name for China.
In the 9th century BC, Feizi, a supposed descendant of the ancient political advisor Gao Yao, was granted rule over Qin City. The modern city of Tianshui stands where this city once was. During the rule of King Xiao of Zhou, the eighth king of the Zhou dynasty, this area became known as the state of Qin. In 897 BC, under the Gonghe Regency, the area became a dependency allotted for the purpose of raising and breeding horses. One of Feizi's descendants, Duke Zhuang, became favoured by King Ping of Zhou, the thirteenth king in that line. As a reward, Zhuang's son, Duke Xiang, was sent eastward as the leader of a war expedition, during which he formally established the Qin.
The state of Qin first began a military expedition into central China in 672 BC, though it did not engage in any serious incursions due to the threat from neighbouring tribesmen. By the dawn of the fourth century BC, however, the neighbouring tribes had all been either subdued or conquered, and the stage was set for the rise of Qin expansionism.