1 Ducat - Ferdinand III Breslau

Ferdinand III was not yet Holy Roman Emperor when these ducats were struck — he held the title of King of Bohemia, under whose authority Breslau (now Wrocław) operated its mint. The Thirty Years' War was actively reshaping Silesia during this window, and the period 1629–1631 saw Imperial forces consolidating control over Protestant-majority territories following the Edict of Restitution in 1629. Breslau's mint output reflected the financial demands of ongoing military campaigns rather than peacetime commerce.

The .986 fineness conforms to the ducat standard established by the Holy Roman Empire — a specification that had held remarkably stable since the late medieval period.