How did low gunports help defenders protect a fortress ditch?

Low gunports were a critical adaptation in fortress design following the advent of gunpowder artillery. By cutting these ports low into the walls, defenders could provide raking fire across the fortress ditch. This strategic placement allowed the garrison to sweep the ditch with cannon and harquebus fire, effectively preventing attackers from approaching the main walls or utilizing siege equipment like battering rams and moving towers.12

This development was part of a broader shift toward a "sunken profile" in military architecture. As fortress walls were lowered and protected by earthen ramparts and a glacis, the use of low-level firing positions ensured that the area immediately surrounding the fortification remained under constant defensive control, neutralizing the threat of infantry assaults within the ditch.21