Qin Shi Huang had work on his enormous mausoleum started early in his reign. The terracotta warriors of the “underground army” guarding the mausoleum, unearthed in 1974, amazed the world.

By 221 B.C. he had unified a collection of warring kingdoms and took the name of Qin Shi Huang Di—the First Emperor of Qin. During his rule, Qin standardized coins, weights, and measures ...