Trojak / 3 Grosze - Jan II Kazimierz Waza Wilno mint

Jan II Kazimierz's reign saw the Commonwealth convulsed by what Poles call the "Deluge" — simultaneous Swedish, Muscovite, Transylvanian, and Cossack invasions that left the treasury in ruins and the coinage in crisis. The Wilno mint, operating in the Grand Duchy of Lithuania, was pressed into producing vast quantities of debased trojaki during the early 1660s to fund ongoing military campaigns, contributing directly to a currency collapse that would plague the Commonwealth for decades.

The 1664–65 issues from Wilno are notorious among specialists for inconsistent planchet preparation, accounting for the weight variation across surviving examples.