When regular coinage became scarce jewelry, silverware and religious vessels were converted into coinage.  Issued in an expedient fashion, they were often roughly shaped, typically squares or diamonds, with a uniface design. When precious metal ran out, other alloys or even paper could be issued, all in the hope that the emergency money would be redeemed after a successful defense.  The opposite was the worse case scenario where one might lose everything.

My example is a silver thaler klippe issued by the besieged city of Münster in 1660 and fits nicely into my Silver Dollars of '60 custom set.  At 34mm x 34mm square and weight close to 28g it may not be silver dollar shaped but certainly has the heft of one.  The uniface design shows the city of Münster's coat of arms with the legend MONAST : WESTPH : OBSESSVM, for Münster Westphalia Beseiged.  It differs from typical siege currency in that it was not from wartime but from an insurrection that began in July of 1660.  The catalog notes from the CNG auction of the Jonathan K. Kern Collection of Siege Coinage provides the following background information:

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As one of the terms of the Peace of Westphalia, the town of Münster was to be ruled by a Catholic prince-bishop. Not long after the treaty was signed, the citizens of Münster rebelled against their ruler, Bishop Christoph Bernhard von Galen. Their goal was to raise Münster to the rank of an imperial free city, thus removing it from the influence of a local prince. In response, Bishop von Galen and his powerful army besieged the city, eventually putting down the insurrection and regaining control in March of 1661.

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