Digital humanities is a remarkable method of identifying historical connections hidden in traditional, analogue historical analysis. As I wrote in November 2015, "Historians soon learn that not all that is present is easily visible." Even relatively small networks, such as the Dunkirk urban intelligence network, profit immensely from digital humanities tools such as Cytoscape, Mindnode, and Palladio.
Article IX of the (in)famous 1713 Treaty of Utrecht stipulated that “all the fortifications of the city of Dunkirk be razed, that the harbour be filled up, and the sluices or moles which serve to cleanse the harbour be levelled.” This was no simple task however, especially given that the Treaty demanded that the destruction be completed in no more than five months. Why did the British and their Dutch allies fear a small maritime city so much?
Despite its diminutive size, seventeenth century Dunkirk kicked far above its weight. Spain, which controlled Dunkirk and the Netherlands until 1646, largely left Dunkirk to manage its own affairs and economy, even granting it duty-free status in 1595. With this free hand, Dunkirk developed an active and dangerous privateering industry. They were so capable, indeed, that when the Dutch decisively defeated the Spanish Armada in the 1639 Battle of the Downs, C.R. Boxer later declared, “The last vestiges of (Spain’s) power at sea – always excepting the Dunkirkers – had been shattered for good and all.” After France finally assumed control of Dunkirk once and for all, Louis XIV’s engineering genius Sébastien Le Prestre embarked on the city’s reinvention as a major naval and maritime port. Most remarkably, he constructed five sea forts: Château d’Espérance, Château Vert, Grand Risban, Château Gaillard, and Fort de Revers, all directly modeled on a 1645 blueprint.
Figure 1: A contemporary representation of Dunkirk’s five sea fortifications.
Figure 2: A 2013 digital model of Dunkirk at its height under Vauban, c.1695. Courtesy fortified-places.net.
But Vauban was not the scheme’s creator, although he assuredly took credit for it. Dunkirk’s new systems resulted from a century-long transfer of planning knowledge, largely from Holland and Italy. The authors of the original 1645 blueprint, Jean Vanden Broek, Balthazar Gerbier, and Jean François Tortarolis, were a joint Franco-Dutch team who credited Maurice, Prince of Orange and leader of the Dutch revolt, as their inspiration. Maurice’s mentor, in turn, had been Simon Stevin, arguably early seventeenth century Holland’s greatest scientist and entrepreneur. He had pioneered the use of circular tower networks, canals, sluices, and vast internal docks – exactly what Vauban eventually installed at Dunkirk. The scheme clearly worked. English pilots feared getting too close to the island fortifications, and the Royal Navy felt threatened by a French naval flotilla so close to the Sussex coast and their bases at Portsmouth and London.
Figure 3: The original, Dutch-inspired sea fortification for Dunkirk, 1645. From “Dessein d’un fort de bois proposé a faire devant la rade de Dunkerque, 1645,” August 4, 1645, AnF-M MAR/D/2/1.
On capturing Dunkirk in 1712, the British moved swiftly to learn as much as possible about the town’s fortifications and economic means. The Secretary of State for the Northern Department appointed John Armstrong and James Abercrombie as directors of a British delegation charged with overseeing Dunkirk’s deconstruction, as well as ferrying any valuable or sensitive urban planning information back to Britain. Armstrong, Abercrombie, and their London counterparts established a series of overlapping networks, some purely official, while others bypassed Parliamentary members and went directly to the monarch and his trusted aide (and friend of engineering surveyors), Lord Charles Townshend.
Figure 4: John Armstrong’s dual communication networks. This system provided him with leverage and eventual patronage from both the Townshend and Walpole families. Courtesy Princeton Center for Digital Humanities.
Armstrong was fascinated by Dunkirk’s beach ‘road’, by the sea fortifications, by Vauban’s ability to suggest both the apparent invincibility of Dunkirk’s defenses and, through the size and depth of its port and docks, the scale of its local economy. As this network map demonstrates, Armstrong leveraged both the official London-Paris diplomatic channel, where he befriended the Walpole family, as well as the more informal but equally important link with Windsor Castle, where Townshend ensured that the upstart engineering surveyor’s reports were essential readings for King George I.
 “Article IX,” The Treaty of Peace and Friendship between the most Serene and most Potent Princess Anne, by the grace of God, Queen of Great Britain, France, and Ireland, and the most Potent Prince Lewis the XIVth, the most Christian King, concluded at Utrecht (London, 1713), 378 .
 “Extrait des Registres dans lesquelles sont Registrez les privileges de la ville et port de Dunkerque,” MAR/D/2/1 ff. 1-3, Archives nationales de France, Marais (AnF-M), Paris.
 Robert Stradling, “Catastrophe and Recovery: The Defeat of Spain, 1639-43,” History 64.211 (1979): 205-19, at 211. Sourced from A. Domínguez Ortiz, The Golden Age of Spain, 1516-1659 (London, 1971), 99 and C.R. Boxer, ed., The Journal of Marten Harpetzoon Tromp, 1639 (Cambridge, 1930), 67. Italics added for emphasis.
 “Act of Queen Anne relating to Dunkirk,” July 31, 1713, Add MS 186 73855 f.5, British Library (BL), London.