The Qin dynasty (Chinese: 秦朝; pinyin: Qín Cháo; Wade–Giles: Ch'in2 Ch'ao2; IPA: [tɕʰǐn tʂʰɑ̌ʊ̯]) was the first dynasty of Imperial China, lasting from 221 to 206 BC. Named for its heartland of Qin, in modern-day Gansu and Shaanxi, the dynasty was formed after the conquest of six other states by the Qin state, and its founding emperor named 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 accomplished a series of swift conquests, first ending the powerless Zhou dynasty, and eventually conquering the other six of the Seven Warring States to gain control over the whole of China. During its reign over China, the Qin sought to create an imperial state unified by highly structured political power and a stable economy able to support a large military. The Qin central government sought to minimize the role of aristocrats and landowners and have direct administrative control over the peasantry, who comprised the overwhelming majority of the population, and control over whom would grant the Qin access to a large labor force. 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 introduced several reforms: currency, weights and measures were standardized, and a uniform system of writing was established. An attempt to restrict criticism and purge all traces of 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. Despite its military strength, the Qin dynasty did not last long. When the first emperor died in 210 BC, his son was placed on the throne by two of the previous emperor's advisers, in an attempt to influence and control the administration of the entire dynasty through him. The advisors squabbled among themselves, however, which resulted in both their deaths and that of the second Qin emperor. Popular revolt broke out a few years later, and the weakened empire soon fell to a Chu lieutenant, who went on to found the Han dynasty. Despite its rapid end, the Qin dynasty influenced future Chinese empires, particularly the Han, and the European name for China is thought to be derived from it.