What failed diplomats were there in ancient China?

The most famous is Jiang Gan, the most failed diplomat. "Jiang Gan stole books" contributed to Battle of Red Cliffs's victory. And Jiang Gan has become a joke forever. It is estimated that Mr. Jiang didn't know how he died in the end ... The Romance of the Three Kingdoms was the most humorous and relaxed passage, and Meng De was in distress situation, so Gong Jin became famous.