Gulden 'Rijnse Goudgulden' - William I

William I of Guelders struck these gulden in direct imitation of the Florentine florin, part of the broader Rhenish monetary alliance — the Kurverein — through which the archbishops of Mainz, Trier, Cologne, and the Count Palatine coordinated gold coinage standards across the Rhine corridor. Guelders was not a founding member of that league, but aligning to its weight and fineness standard was commercially necessary for a duchy whose trade routes ran straight through the Rhenish heartland.

The span 1371–1402 encompasses William's turbulent relationship with Brabant, including the aftermath of the 1371 Treaty of Nimwegen.