于禁
In 192, after the warlord Cao Cao took charge of Yan Province, Yu Jin and his fellow volunteers were appointed as "doubo"s (都伯; an officer leading 100 men) and placed under the command of Wang Lang. Wang Lang felt that Yu Jin was extraordinary and had the potential to become a great general, so he recommended Yu Jin to Cao Cao. Cao Cao commissioned Yu Jin as a Major () after interviewing him, and then sent him to attack Guangwei (), a location in Xu Province, which was governed by Tao Qian. Yu Jin successfully conquered Guangwei and was promoted to Commandant Who Breaks Formations ().