After thinking through the attack plan, Yang Zhengshan handed Chongshan Pass over to Zhou Lan, who had recovered somewhat, at the end of April, and personally led the Front Battalion of Chongshan Town, the Rear Battalion, and the Central Battalion to Dinghu Guard.
At the same time, he ordered Assistant General Zhang Chengzhi of the East Route Songzhou Guard, Assistant General Niu Zhuang of the Central Route Jianning Guard, Assistant General Tang Feihu of the Central Route Jinzhou Guard, Assistant General Qin He of the South Route Dingliao Guard, Assistant General Yang Mingzhi of the North Route Fuzhou Guard, and Assistant General Yang Mingwu of the North Route Heishan Guard to lead their elite troops to Dinghu Guard to rendezvous.
The Zhenbiao Front, Middle, and Rear Battalions, besides their previously assigned warhorses, brought an additional thirty thousand warhorses. They raced all the way in a storm of wind and fire, taking only three days to cover more than four hundred li and arrive at Dinghu Guard.
Dinghu Guard's guard city was located at Guan Shankou. This was both the site of Dinghu Guard's guard city and the station of the Assistant General's Shogunate.
A large amount of fertile farmland had been opened up in the valley south of Guan Shankou for the military households of Dinghu Guard to cultivate, while north of Guan Shankou lay vast stretches of pasture and barracks.
Standing on the mountain peak west of Guan Shankou and looking north, one could see watchtower forts forming line after line, extending toward the northeast.
The garrisons under the jurisdiction of the West Route Dinghu Guard Assistant General's Shogunate were precisely these watchtower forts.
These watchtower forts crossed vast stretches of grassland, and four guard cities had also been built beside several small rivers to the north. The guard