Definition of a Papal Bull
The word, bull comes from the Latin, bubble. It is the lead seal that was appended to the end of a document acting as the signature of the pope. On one side, it contains the pope’s name and on the other, images of Saints Peter and Paul from whom he is given his authority.
On this particular bull, Pope Paul III’s coat of arms is actually on it, which is interesting.
The bull is generally an official document of the Holy Father. We know by the choice of threading used, either silk or twine, the importance of any particular bull.