郭嘉
Xun Yu's contributions to Cao Cao's forces and administration are immense. On one hand he recommended many other men of calibre to Cao Cao, including Xun You (his second cousin-nephew), Chen Qun, Zhong Yao, Guo Jia and Sima Yi, creating a body of advisors around Cao; at the same time he participated in several battles and major events of the era, often giving timely advice to his lord. Cao Cao, in turn, respected Xun Yu greatly and placed great store in his advice.