5 Zlotys Denarius of Boleslaw I the Brave

Bolesław I was the first king of Poland, crowned in 1025 just months before his death, though his rule as duke stretched back to 992. The denarius referenced here was among the earliest Polish coins ever struck — crude, often poorly centered issues produced at a time when the Piast dynasty was actively constructing a monetary economy from scratch, partly to pay the Church and fund military campaigns against the Holy Roman Empire and Kievan Rus simultaneously.

This 2013 commemorative is part of NBP's long-running series resurrecting medieval Polish coin types. The original denarii it references survive in very small numbers, mostly in ecclesiastical hoards.