When the Qing army invaded, Ngo Thi Nham had a good plan: retreating the Navy to Bien Son, retreating the army to defend the Tam Diep line to preserve the force, he advocated “Both sides fighting and holding are not a good plan. In the end, there is only one way to tell the Navy to load the ships with provisions, smoothly set sail, and go straight to the seaport to the Bien Son area to station troops. The soldiers prepared their weapons, sounded drums, and headed back to defend Tam Diep mountain. The two sides, the navy and the army, contacted each other, held key positions and waited for the lord to come, then we would fight decisively. The good generals of ancient times anticipated the enemy’s position before fighting, grasped the victory and then acted, and planned ahead according to the changing situation. Now we will preserve our military strength and retreat without losing a single arrow. Let them stay overnight and then chase them away”

Excerpted from Hoang Le Nhat Thong Chi – p342