Repair works on the Rhine riverbank wall in Basel, Switzerland, have uncovered a seal stamp that belonged to the late 13th century cantor of Basel cathedral.The seal was discovered last month during underwater archaeological excavations at the foot of the Pfalz, the viewing terrace overlooking the Rhine behind the Mnster Cathedral. Pfalz is derived from the Latin word for palace and the terrace is named after the bishops palace which used to be next to it. The cathedrals cloister can be accessed directly from a gateway on the Pfalz.The pointed oval seal die is made of brass and is in excellent condition. It depicts a man in ecclesiastical robes standing at a lectern holding a large book. A cantor was a churchs choir master who selected the music, led the chants during mass and sang the solo parts. He also played an important administrative role as a manager of the liturgical library, who was in charge of updating the cathedrals records (deaths, charters, annals, etc.).Surrounding the image on the edges of the seal is the inscription ECCE(LESIA).BASILIEN(SIS) + S(IGILLVM) RVDOLFI.CANTORI, meaning Cathedral of Basel, Seal of Rudolph Cantor. Surviving records identify the seal owner as cathedral cantor Rudolf Kraft who lived at what is now Augustinergasse 8 in Basel between 1296 and 1305, literally a minutes walk from the Pfalz.Basel wasnt even part of the Swiss Confederacy when this seal was in use. That happened 200 years later when the Canton of Basel joined the confederation in 1501. The renovation of the riverbank wall has brought to light remains from 2,000 years of the citys history and every period from then to now.The riverbank wall and the Mnsterfhrbdeli landing stage are currently being renovated to protect the historic structures on Basels Rhine riverbank. The muddy excavated material is being systematically examined with metal detectors by the Archaeological Soil Research team. Depending on visibility, Basel archaeologists are using underwater cameras and drones for the first time. This approach allows for the most precise possible documentation of the archaeological structures and finds, even under difficult conditions.The archaeological discoveries at this location are no coincidence. As early as the winter of 1932/33, 580 Roman-era coins and numerous medieval objects were unearthed during periods of low water. For centuries, waste, rubble, and building materials from the Palatinate and the bishops residence were dumped down the slope into the Rhine. Collapses, such as the Rhine slope collapse in 1346 and the Palatinate in 1502, also contributed to the numerous objects sliding into the river.