Brunswick issued its own notgeld coinage in iron during 1920 because the postwar German central government couldn't produce enough small-denomination coins to meet demand — a shortage driven partly by wartime metal requisitions and partly by the chaos of demobilization. The duchy had ceased to exist as a sovereign state in 1918 with the abdication of Duke Ernst August, so this coin was technically issued by a government body administering a defunct monarchy's territory.
The iron composition was a direct legacy of wartime substitution policy, not a peacetime choice.
Brunswick issued its own notgeld coinage in iron during 1920 because the postwar German central government couldn't produce enough small-denomination coins to meet demand — a shortage driven partly by wartime metal requisitions and partly by the chaos of demobilization. The duchy had ceased to exist as a sovereign state in 1918 with the abdication of Duke Ernst August, so this coin was technically issued by a government body administering a defunct monarchy's territory.
The iron composition was a direct legacy of wartime substitution policy, not a peacetime choice.