Sima Yu
Around the new year 352, Huan, upset that his requests to lead armies north had been rebuffed by Yin and Sima Yu, mobilized his troops and gestured as if he were about to attack the capital. Yin was shocked, and initially considered either resigning or send the imperial banner of peace ("Zouyu Fan", 騶虞幡) to order Huan to stop. After advice from Wang Biaozhi (王彪之), however, he instead asked Sima Yu to write a carefully worded letter to Huan, persuading Huan to stop.