Zang Ba
During Cao Cao's battles with Yuan Shao in the early 200s, Zang Ba led elite soldiers into Qing Province, allowing Cao Cao to focus the majority of his soldiers on the main battles at hand, and not having to worry himself about the east. Later, when Cao Cao defeated Yuan Tan in the Battle of Nanpi, Zang Ba went personally to Cao Cao to congratulate him on his great victory. During the celebration banquet, he offered to move his family to Ye city, Cao Cao's headquarters, effectively as hostages to bound his loyalty. Cao Cao refused, expressing his full confidence in Zang.