Denar - Siemowit III Elder Płock mint

Siemowit III ruled Masovia for over five decades, outliving multiple Polish kings and navigating the duchy through shifting allegiances between the Piast line and the expanding Jagiellonian orbit. His Płock mint operated under ducal rather than royal authority — Masovia remained an autonomous duchy until 1526, nearly a century and a half after his death, which gave local coinage here a distinct administrative independence from the Cracow-centered monetary system.

Kopicki 223 is among the better-documented Masovian denars of this period, though attribution of individual pieces remains contested given die-sharing practices common to smaller Polish mints of the fourteenth century.