Records of the Three Kingdoms
Cao Zhen, courtesy name Zidan, was a younger clansman of Cao Cao. His father Cao Shao died early and Cao Cao raised the son. Hunting a tiger and service in the field made his name. Under Cao Pi he was enfeoffed, and he was among those charged to assist Cao Rui.
When Zhuge Liang campaigned north, Cao Zhen repeatedly commanded the armies in the west. In 228 Shu came out at Qishan and Zhang He broke Ma Su at Jieting; Cao Zhen was one of the commanders on that front. The next year Zhuge Liang moved on Chencang. Hao Zhao held the city, and Shu withdrew when the grain failed. Cao Zhen once planned a multi-pronged invasion of Shu and stopped it when heavy rain broke the roads. He died of illness in 231. His son Cao Shuang was later named, with Sima Yi, to assist Cao Fang, and in 249 Sima Yi destroyed him.
Romance of the Three Kingdoms
In the novel Cao Zhen faces Zhuge Liang more than once. At Chencang, Hao Zhao holds the city by every method the book can invent, and Zhuge Liang cannot break it. Cao Zhen himself is sometimes shamed by a letter from Zhuge Liang and sickens from rage.
The histories do not make the illness the result of a letter. Hao Zhao’s defense of Chencang is the firmer campaign in this stretch, and the novel spends pages on it.
Reference: Wikipedia · Cao Zhen