Qin dynasty

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 13th 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.

The Qin sought to create a state unified by structured centralized 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, and a massive new national road system, as well as the city-sized Mausoleum of the First Qin Emperor guarded by the life-sized Terracotta Army.

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.