Grosz litewski - Sigismund III Vasa Wilno, bust

The Lithuanian grosz occupied an awkward administrative position throughout Sigismund III's reign — nominally integrated into the Commonwealth's currency system yet minted at Wilno under separate Lithuanian treasury oversight, which produced chronic inconsistencies in billon fineness across the run. The brief spike to .359 silver between 1607 and 1610 almost certainly reflects a short-lived reform attempt rather than stable policy; the alloy dropped back without formal announcement.

Sigismund's near-constant warfare — against Sweden, Russia during the Time of Troubles, and the Ottoman frontier — drained bullion reserves and kept mint output under pressure for most of these decades.