Tajemniczy brat Jakub - czternastowieczny lektor dominikański (przyczynek do studiów nad średniowieczną sfragistyką i monastycyzmem)

The article presents a thorough interpretation of a seal stamp, found during the archaeological excavations at the northern side of the Sacred Mary Church in the Poznań Cathedral Island (Ostrów Tumski). The stamp is dated to the period between the end of the 13th and the first half of the 14th century. This chronology is based upon its form and elements of its decoration. A legend inscribed on the stamp’s frame, informing that its belonged to James - a lector of the preacher order, made possible to identify a social status of the owner along with his position in the Dominican structure. Unfortunately, neither connection between James and any concrete order nor whereabouts of his stay at Ostrów Tumski were recognized. These questions might be answered only after more detailed studies of the Dominican related archives are carried out.