However, when cannons and guns came into wider use in the fifteenth century, the power of bullets with gunpowder reduced the superiority of height, while cannons destroyed high and relatively thin walls with ease while high buildings became excellent targets for cannons.
しかし、15世紀にはいり大砲、銃が活躍し出すと、火薬を使った銃弾の威力は高さの優位を減少させ、大砲の使用により高いが比較的薄い壁は容易に打ち壊され、また高い建造物は大砲の標的となった。