The essential point, constantly in Cao Cao’s mind and in the thoughts of his more astute companions, was that while a reputation for open dealing was desirable, it could not be gained by excessive informality or loss of dignity. That way led to a failure of authority, and a man in Cao Cao’s position could not afford to ignore any show of disrespect or abuse of favour. There was a definite, albeit undrawn, line, and those who crossed it were in dangerous territory.
Rafe de Crespigny, Imperial Warlord: a biography of Cao Cao 155-220 AD
A lesson in leadership, of a certain kind.
Cao Cao was prickly, even for a warlord, and routinely had those who offended him executed. Once, from a tower in the grounds of his residence, he caught sight of one of his daughters-in-law wearing a robe of embroidered silk, in contravention of his rules against lavish living – she was sent back to her paternal family and ordered to kill herself. He was demonized in official history and folklore for craftiness and cruelty.
Yet he was a reformer who brought stability and civil administration to the lands under his control, amid the decades-long turmoil at the close of the Han dynasty; he accepted criticism and had a habit of recruiting and retaining the loyalty of capable officials, many of whom had previously served his bitter foes; he was a brilliant tactician and strategist and a brave soldier, often fighting in the vanguard of his troops; and he was a talented poet who was generous and self-aware, and who presided over a period of cultural flourishing.