 Ming prefectural and provincial capital walls were ten to twenty meters thick at the base and five to ten meters at the top.In Europe the height of wall construction was reached under the Roman Empire, whose walls often reached ten meters in height, the same as many Chinese city walls, but were only 1.5 to 2.5 meters thick.Rome's Servian Walls reached 3.6 and 4 meters in thickness and 6 to 10 meters in height.