1 Thaler 'Conventionsthaler' - Frederick Charles Joseph of Erthal

Frederick Charles Joseph von Erthal was the last Archbishop-Elector of Mainz to actually govern from the city. French revolutionary forces seized Mainz in October 1792, were briefly expelled, then retook it permanently in October 1793 — meaning this 1794 thaler was struck by an elector who had already lost his seat and was issuing coin from exile. He died the following year, and the ancient ecclesiastical electorate effectively died with him; the Reichsdeputationshauptschluss of 1803 formally dissolved what remained.