Rhuddlan makes Denbigh maritime

Denbigh is not beside the sea or a river, yet it belonged to a wider maritime system through Rhuddlan Castle, roughly three hours away on foot. Ships could land troops and supplies at Rhuddlan on the tide, while forces could also approach Denbigh from neighbouring strongpoints. A commander could rest the landed troops and march the next day or use the remaining half-day for an immediate advance. Maritime access did not have to reach the inland fortress directly when a secure landing place lay within a short march. Coastal castles, shipping, and overland movement could therefore operate as one reinforcement and relief system.