窦建德
Meanwhile, there was another major rebel leader nearby—Gao Tansheng (), a Buddhist monk who had seized Huairong and claimed the title of Dacheng Emperor (i.e., Emperor of Mahayana). Gao Tansheng sent messengers to persuade Gao Kaidao to submit to him, and Gao Kaidao agreed. Gao Tansheng created him the Prince of Qi, but several months later, Gao Kaidao assassinated Gao Tansheng, taking over Gao Tansheng's troops and making Huairong his capital. Both he and another rebel leader, Dou Jiande, tried to get Luo Yi, who then occupied You Prefecture (幽州, roughly modern Beijing), to submit, but Luo refused, submitting instead to Tang Dynasty.