section_path: Reign as King of Qin/Unification of China
section_name: Unification of China
paragraph_text: Unification of China
  
  In 230 BC, King Zheng began the final campaigns of the Warring States period, setting out to conquer the remaining six major Chinese states and bring China under unified Qin control.
  
  The state of Han, the weakest of the Warring States, was the first to fall in 230 BC. In 229, Qin armies invaded Zhao, which had been severely weakened by natural disasters, and captured the capital of Handan in 228. Prince Jia of Zhao managed to escape with the remnants of the Zhao army and established the short-lived state of Dai, proclaiming himself king.
  
  In 227 BC, fearing a Qin invasion, Crown Prince Dan of Yan ordered a failed assassination attempt on King Zheng. This provided casus belli for Zheng to invade Yan in 226, capturing the capital of Ji (modern Beijing) that same year. The remnants of the Yan army, along with King Xi of Yan, were able to retreat to the Liaodong Peninsula.
  
  After Qin besieged and flooded their capital of Daliang, the state of Wei surrendered in 225 BC. Around this time, as a precautionary measure, Qin seized ten cities from Chu, the largest and most powerful of the other Warring States. In 224, Qin launched a full-scale invasion of Chu, capturing the capital of Shouchun in 223. In 222, Qin armies extinguished the last Yan remnants in Liaodong and the Zhao rump state of Dai. In 221, Qin armies invaded the state of Qi and captured King Jian of Qi without much resistance, bringing an end to the Warring States period.
  
  By 221 BC, all Chinese lands had been unified under the Qin. To elevate himself above the feudal Zhou kings, King Zheng proclaimed himself the First Emperor, creating the title which would be used as the title of the Chinese sovereign for the next two millennia. Qin Shi Huang also ordered the Heshibi to be crafted into the Heirloom Seal of the Realm, which would serve as a physical symbol of the Mandate of Heaven, and would be passed from emperor to emperor until its loss in the 10th century.
  
  During 215 BC, in an attempt to expand Qin territory, Qin Shi Huang ordered military campaigns against the Xiongnu nomads in the North. Led by General Meng Tian, Qin armies successfully routed the Xiongnu from the Ordos Plateau, setting the ancient foundations for the construction of the Great Wall of China. In the South, Qin Shi Huang also ordered several military campaigns against the Yue tribes, which annexed various regions in modern Guangdong and Vietnam.