10 Kreuzers - Francis Joseph I

The billon 10 Kreuzer was introduced as part of Austria's post-1857 currency reform, the Vereinsmünze agreement that attempted to harmonize coinage across the German states. Vienna's participation locked the empire into a fixed weight-fineness standard just as the fiscal pressures of the Italian wars were mounting — a structural problem that would eventually force Austria off silver convertibility entirely by 1866.

The .500 fineness was itself a political compromise, sitting below the purity of the larger silver denominatons to control bullion costs.