The Qin State, located in modern-day Shaanxi Province, rose to prominence during the Warring States period (475-221 BC). Under the leadership of King Ying Zheng (259-210 BC), also known as Qin Shi Huang, the Qin State embarked on a series of military campaigns to conquer the other six major Warring States. These campaigns were characterised by the Qin's superior military organisation, discipline, and use of advanced weaponry, such as iron weapons and crossbows. The Qin armies were led by talented generals such as Wang Jian and Meng Tian.
In a systematic and methodical manner, the Qin State conquered the Han State in 230 BC, the Zhao State in 229 BC, the Wei State in 225 BC, the Chu State in 223 BC, the Yan State in 222 BC, and finally, the Qi State in 221 BC. With the conquest of Qi, the Qin State had achieved the unification of China under its rule, marking the beginning of the Qin Dynasty (221-206 BC).