English: A medieval lead Papal bulla of Pope Innocent III, 1198-1216. The obverse of the bulla contains the legend INNOCENTIVS PP III, PP standing for 'Pastor Pastorum' or 'Shepherd of Shepherds'. The obverse has a border of pellets. On the reverse can be seen depictions of Saints Peter and Paul beneath an inscription reading SPASPE (an abbreviation standing for St. Paul and St. Peter). St. Paul is seen on the left of the seal looking right, with a long pointed beard, while St. Peter is on the right facing left and has a rounded face with beard and hair formed of pellets. Both faces are contained within beaded borders and separated from one another by a crozier. Like the obverse type, the reverse has a border of pellets. This example measures 38.86mm in diameter, 6.28mm in thickness, and weighs 52.78g. Papal bullae such as this would have acted as seals on official Papal documents to authenticate their provenance and authority.