10 Ducats - Aureus Magnus Bremen

This is a restrike of a historical Bremen municipal gold piece, produced in 1958 as a bullion-adjacent prestige issue rather than circulating currency — the Federal Republic had no business striking ducats, a denomination dead for over a century, but civic commemorative tradition in German free cities ran deep enough to justify it. Bremen's senate had a long history of commissioning large-format gold multiples for diplomatic gifts and civic ceremony, a practice stretching back to the seventeenth century.

The X# prefix in the Krause reference places it firmly in the "unofficial" category — legal tender nowhere, but recognized as a coherent series by collectors.