This bulla has the name of Pope Celestine III on the verso. He was elected Pope in 1191 and continued until 1198.
Obverse: Heads of the apostles Peter and Paul, the founders of the Church of Rome with SPASPE (Sanctus PAulus and Sanctus PEtrus) above
The reverse (verso) of the bulla shows the name of the Pope, which is written in the nominative, with his abbreviated title. It reads ‘CELE / STINVS / PP • III’ within a beaded border. The ‘PP’ has an ‘Ω’ above.…

So far I cannot find the pope’s name on the complete popes list links above.
If you can help please add your comments below…

Weight: 44.13 g
Size: 38.73