sentences:  In the eighth month of 1213, the general Heshilie Zhizhong (紇石烈執中; also known as Hushahu 胡沙虎) rebelled against the emperor, Wanyan Yongji, and assassinated him.Hushahu then installed Wanyan Congjia on the throne to replace Wanyan Yongji.As Wanyan Congjia was stationed in Hebei at the time, Hushahu chose Wanyan Congjia's eldest son, Wanyan Shouzhong (完顏守忠), to temporarily serve as "jianguo" (監國; regent) in the capital, Zhongdu (中都; present-day Xicheng and Fengtai districts of Beijing).