Emperor Yang of Sui

Yang Guang was renamed by his father after consulting oracles, made Prince of Jin in 581, then given command of five armies that crushed the Chen dynasty in 588. Those victories and quiet work against his older brother made him crown prince in 600. His father died in 604 — most historians believe Yang Guang ordered the murder, though it's unproven — and he took the throne. He completed the Grand Canal, rebuilt the Great Wall, and sent expeditions that brought Sui to its greatest size, including a conquest of Champa that killed thousands of his own soldiers from malaria. Then came the Goguryeo…