Casimir III Grosz

Casimir III's grosz introduced a standardized silver alloy that halved the weight of previous Polish coins, making transactions more efficient across his realm.

This reform coin, struck mainly in Kraków, featured a simple design: the king's bust on one side, a Polish eagle on the other. Casimir aimed to modernize the economy after years of chaotic currency. He borrowed from Bohemian models, adapting the groschen to local needs. That decision stabilized trade routes stretching from the Baltic to the Black Sea.

Exact mintage figures are murky; records from the 14th century weren't exactly meticulous. What we do know is that production ramped up in the 1360s as his reforms took hold.

One oddity: the grosz's edge sometimes shows filing marks, likely from scrappy mint workers trying to stretch their silver. Not the most glamorous detail, but it speaks to the era's realities.