Silvery dawn: the first use of local silver in early Piast coinage (11th–12th century Poland)

This study investigates whether locally available silver contributed to early Piast coinage through high-resolution lead isotope and elemental analyses of 11th–early 12th-century coins from the Polish lands. The earliest royal issues, including key emissions of Bolesław I the Brave, form an isotopically coherent group consistent with the Pb–Ag ores of the Upper Silesia-Kraków Upland (US). Although these deposits were already known and exploited as a source of lead in earlier periods, the present results provide the earliest well-documented evidence for the contribution of silver isotopically compatible with this ore province to Piast monetary production. Selected later Piast issues show comparable isotopic characteristics, suggesting continuity in the use of this regional bullion source. Individual Bohemian and Hungarian coins show compatible isotopic signatures, suggesting that silver compatible with the US isotopic field also entered wider Central European circulation. In contrast, cross deniers and other contemporary issues reflect mixed bullion pools, including recycled oriental and European silver. Together, these findings indicate that silver isotopically compatible with the US ore province formed an important component of early Piast monetary production within broader regional exchange networks.