Ducat - Johann Konrad I von Roggenbach

Johann Konrad I von Roggenbach held the see of Basel for less than four years, dying in office in 1662 before he could consolidate much of a monetary program. The Bishopric itself was an anachronism by this point — its temporal authority had been eroding since Basel the city formally joined the Swiss Confederation in 1501, leaving the prince-bishops governing a truncated territory centered on Porrentruy rather than the city that gave the diocese its name.

The brief reign window of 1659–1662 tightly constrains surviving examples to a small production window, and Faehnders' census work on HMZ 2#136 confirms genuinely low survivor numbers.