Cao Cao

Cao Cao started as a minor Han official in the 150s AD, but the dynasty's collapse became his opening. By the 190s he'd raised his own army, seized Yan Province, and in 196 took custody of Emperor Xian, the hostage sovereign no other warlord could hold. From a new capital at Xuchang, Cao Cao crushed rivals one by one—Lü Bu, Yuan Shu, Zhang Xiu—then broke the northern powerhouse Yuan Shao at Guandu in 200. Seven years of grinding campaigns followed, unifying the north under his hand. His 208 push south shattered at Red Cliffs; the Yangtze remained out of reach. He took the title Duke of Wei in…