In winter 755, An launched his rebellion on 16 December, claiming he had received a secret edict from Emperor Xuanzong to advance on Chang'an to remove Yang. The imperial officials were all apprehensive, because An had the strongest troops of the realm at the time, except for Yang, who believed that An could be suppressed easily. Emperor Xuanzong commissioned the general Feng Changqing as military governor of Fanyang and Pinglu, intending to have him replace An after An's rebellion was defeated. The Emperor also sent Feng to the eastern capital, Luoyang, to build up the defense there; another general, Gao Xianzhi, was ordered to command a secondary defense at Shan Commandery (陝郡, roughly modern Sanmenxia, Henan). He executed An Qingzong and An's first wife Lady Kang, and forced An Qingzong's present wife, Lady Rongyi, to take her own life.