 To achieve this, Shanhaiguan needed to be taken, so a Fengtian strike force had to be in the region of Xujialing (徐家岭) on the western bank of Shi He (石河), as well as the adjacent regions to the north and south of Xujialing.Once these regions were secured, Fengtian forces would need to gather near Shanhaiguan and launch an assault to capture it.This task force would consist of the 1st Army and 2nd Army, designated as a Combined Corps.