The Qin Dynasty (Chinese: 秦朝; pinyin: Qín Cháo; Wade–Giles: Ch'in Ch'ao; IPA: [tɕʰǐn tʂʰɑ̌ʊ̯]) was the first imperial dynasty of China, lasting from 221 to 206 BC. The Qin state derived its name from its heartland of Qin, in modern-day Gansu and Shaanxi. The strength of the Qin state was greatly increased by the legalist reforms of Shang Yang in the 4th century BC, during the Warring States Period. In the mid and late third century BC, the Qin accomplished a series of swift conquests, first ending the powerless Zhou Dynasty, and eventually conquering the remaining six states of the major states to gain control over the whole of China, resulting in a unified China.

During its reign over China, the Qin Dynasty achieved increased trade, improved agriculture, and military security. This was due to the abolition of landowning lords, to whom peasants had formerly held allegiance. The central government now had direct control of the masses, giving it access to a much larger workforce. This allowed for the construction of ambitious projects, such as a wall on the northern border, now known as the Great Wall of China. The Qin Dynasty also introduced several reforms: currency, weights and measures were standardized, and a better system of writing was established. An attempt to purge all traces of the old dynasties led to the infamous burning of books and burying of scholars incident, which has been criticized greatly by subsequent scholars. The Qin's military was also revolutionary in that it used the most recently developed weaponry, transportation, and tactics, though the government was heavy-handed and bureaucratic.