Is “Defeating Yuan Shao at the Battle of Guandu and unifying the north” true?
attested in history
The Records of the Three Kingdoms, Book of Wei, Annals of Emperor Wu, records that Cao Cao defeated Yuan Shao's main forces at Guandu with fewer troops, then pacified the Wuhuan, and basically unified northern China.
Cao Cao
In official histories, he is an outstanding statesman, military strategist, and writer, while in novels, he is portrayed as a treacherous and cruel usurper.