In the mid-nineteenth century the complex relationship between Britain, France and the Channel Islands acquired a new urgency, as the British state launched a massive project to create an artificial harbour on the Island of Alderney, the lynchpin of a system of maritime security that would ensure the safety of British merchant shipping in wartime, countering the threat posed by the rapidly advancing naval base and fortified harbour at Cherbourg. In the event of war Braye Harbour would be critical to Britain's global system, the physical manifestation of a distinctive maritime culture and the strategic methods of a unique seapower state. Together with a second new harbour at Portland, 60 miles north, it would enable the Royal Navy to control the western entrance of the English Channel, isolating Cherbourg from the French naval bases on the Atlantic and Mediterranean coasts. This massive, costly project, the product of an era of heightened Anglo-French tension, exploited the latest engineering expertise to address the strategic problem of commanding the seas with short-ranged steam ships. But Braye was only the latest in a long line of developments that linked the Channel Islands into the British strategic system and, like those that had gone before, it changed the relationship between Britain, France and the Islands, and the Islands themselves. How should we understand the interlocking relationships between great powers and small islands, terrestrial identities and maritime realities? The conflicted history of Braye Harbour suggests an ambitious cultural reading could offer a way forward.

Early in 1862, as the British House of Commons prepared to decide whether to continue funding the massive naval harbour project at Braye, geologist, mining engineer and author David Thomas Ansted (1814−80) elevated a humdrum issue of expenditure and engineering onto an altogether higher plane. Ansted presented the harbour and fortress complex as the key to naval dominion, and a totem of national culture. His article ‘England's “Broad Stone of Honour”’ linked the great Prussian fortress of Ehrenbreitstein, looming over Coblenz at the confluence of the Moselle and the Rhine, the key to the defence of Germany, with the new bastion that secured command of the English Channel: they were the representative bulwarks of their respective countries.