'They Hide from Me, Like the Devil from the Cross': Transalpine Postal Routes as Intelligence Work, 1555-1645

Tracing patterns of letter interception across the Alps provides a new geography of Habsburg communications, espionage, and counter-espionage in seventeenth-century Europe. Using the correspondence of the Tassis family of imperial and Spanish postmasters, this article demonstrates that despite increasingly martial rhetoric, battles in information security took place along different geography than the military campaigns of the Thirty Years War. Instead of the 'Spanish Road', the article proposes the consideration of two alternative roads debated by postal administrators: the 'German Road' through Augsburg and the 'Swiss Road' through Lucerne. Letter interceptions along these roads demonstrate that information security differed from martial security in two key ways: First, Habsburg postal systems relied upon international cooperation rather than territorial control. The desire to avoid information leaks had to be balanced with the financial necessity of contracting postal operations to Alpine towns such as Lindau. Second, postmasters themselves responded to the information security needs of cosmopolitan private patrons and multiple princes, complicating their allegiances as state agents. Cases such as the imperial Postmistress General of Brussels and Spanish postmaster of Milan demonstrate that postmasters served as both 'honorable spies' and spy-catchers, proposing new itineraries to circumvent espionage.