This paper presents the results from analysis of thirty 12th to 13th century glass bangles from Czermno, eastern Poland. Study of the primary glass composition was carried out by laser ablation ICP‐MS and electron probe microanalysis. Lead isotope analyses were conducted to determine the origin of the glass's main raw material. Two types of lead glass were distinguished, high‐lead glass and Slavic lead ash glass, both of which were common in Central and Eastern Europe in the early Middle Ages. Isotopic investigations show that the lead flux for the Slavic glass likely came from the Cracow–Upper Silesia region in southern Poland.