A maritime tradition of British fortification

The Ring of Iron belongs to a longer British pattern of fortifications tied to the sea. Henry VIII's chain of artillery forts guarded harbors, could be supplied by ship, and denied an enemy access from the water. Martello towers continued the practice of constructing related defensive sites against maritime danger. Hadrian's Wall was also anchored on both coasts, where sea control helped sustain its large bases. Fixed defenses and maritime logistics were intertwined long before Edward I.