Excerpts from Books and Wikipedia
Zheng became king of Qin in -246. He was just 13 years old. At the age of 21, he began eliminating the six rival states. Qi, in the northeast, was the last to fall in -221. In 1974, the Terracotta Army of more than 7,000 warriors was discovered by men digging a well. The life-sized clay soldiers had stood guard close to the body of the First Emperor for over 2,000 years. [Furtado: 1001 Days]