Cao Cao (曹操, pronounced "Tsao Tsao") (155-220) was the self-appointed Imperial Secretarist of the Han Dynasty and the de facto ruler of Northern China (as the Kingdom of Wei) during the beginning of the period of Three Kingdoms. He was a brilliant ruler, strategist and poet. Cao Cao had twenty five sons; his consort Lady Bian gave birth to four sons: Cao Pi, Cao Zhang, Cao Zhi and Cao Xiong. Cao Zhi was regarded as the greatest poet of the age.
The historical Cao Cao was the son of a court official of the Han Dynasty. Cao Cao himself held positions at this court until an attempted coup by general Dong Zhuo brought down the dynasty. Dong Zhuo was not able to consolidate his hold on the empire and China fell into civil war and anarchy. Cao Cao was part of the Alliance against the Dong Zhuo-contolled Han Dynasty. He quickly gained fame by winning several battles against the Han which earned him the name the "Hero of Chaos" (梟雄 Xiao Xiong).
In the resulting chaos Cao Cao emerged as the military ruler of northern China, winning a critical battle (the Battle of Guandu) at the Yellow River. He assumed effective rule of Northern China and assumed the title of Imperial Secretarist. The last Han emperor would remain a figurehead until the abdication in 220. Cao Cao extended his control northward, past the Great Wall of China, into northern Korea, and southward to the Han River. His attempt to extend his domination south of the river Chang Jiang was dashed as his forces were defeated by the coalition of Liu Bei (who later founded the Kingdom of Shu in southwestern China) and Sun Quan (who later founded the Kingdom of Wu in southeastern China) at the naval Battle of Red Cliff in 208.
In 213, he was titled Wei Gong (Duke of Wei) and given ten cities as his domain. This area was named the "State of Wei". In 216, Cao Cao was promoted to Prince of Wei.
Cao Cao died in 220 due to a brain tumor. He was posthumously given the title of Wei Wang (King of Wei). His eldest surviving son Cao Pi inherited his position as Imperial Secretarist and the title Wei Wang. Within one year Cao Pi seized the imperial throne and proclaimed himself to be the first Emperor of the Wei Dynasty - usually referred as the Kingdom of Wei.
While the historical record indicates Cao Cao was a brilliant ruler and poet, in classical Chinese literature he is traditionally represented as a cunning and deceitful general. Cao Cao is also a character in the Chinese classic Romance of the Three Kingdoms, where he is cast as the cunning and capable villain. This is likely due to a subsequent Confucianist interpretation of events which would have attributed his failure to unify China to flaws in his character.
"I would rather betray the world, than let the world betray me"
-- Cao Cao, Romance of the Three Kingdoms (fictional)