When Philippe II, king of France, captured the duchy of Normandy from King John in 1204, the strategic balance in the English Channel was permanently transformed. From Dieppe to La Rochelle, the entire continental coastline now lay firmly under French control, threatening England’s dominance as the ‘principal naval and maritime power in the northern seas’. For Kent, the long-term ramifications of this geopolitical shift were equally far-reaching in terms of its strategic significance. The county, for instance, was no longer secure. Just twenty-one miles separated Dover from the French-controlled harbour at Calais. If wind and tide were favourable, an invasion fleet could cross within a single day. All 350 miles of the Kentish coastline, especially the section running from Dungeness to Pegwell Bay, were vulnerable to cross-channel raids, which could be launched without warning from continental ports like Boulogne. The county’s geographical proximity to France also ensured that the Dover Straits became the primary conduit for England’s transmarine lines of communication with its continental allies, as alternative routes from more westerly Channel ports were highly susceptible to interdiction. Commerce too became increasingly hazardous as enemy privateers, now operating from formerly friendly ports like Dieppe, attacked English shipping.

Given Kent’s position on the proverbial frontline and its vulnerability to transmarine assault, the Crown devoted considerable effort and resources on maintaining its maritime defences. But before an analysis of these measures is undertaken, consideration must be given to what is actually meant by the term ‘maritime defence’. One definition could be the ‘protection of coasts and ports, together with any shipping in adjacent waters, by such naval … forces allotted to this purpose’. Yet its scope is far broader than just coastal defence, potentially encompassing any governmental policies/programmes, logistics, operational activities and physical structures intended to protect a seacoast and its surrounding waters. Command hierarchies that issued and executed orders, for instance, controlling either the disposition of counter-invasion forces along the shoreline or the handling of a fleet at sea, would fall within this definition. So too would the vessels and crews that patrolled the Channel to safeguard the coastline during invasion scares or to enforce trade embargoes.