Papal Bull - Seal

Seal

The most distinctive characteristic of a bull was the metal seal, which was usually made of lead, but on very solemn occasions was made of gold (as Byzantine imperial deeds often were). It depicted the founders of the Church of Rome, the apostles Peter and Paul, identified by the letters Sanctus PAulus and Sanctus PEtrus. The name of the issuing pope is on the reverse side. This was then attached to the document either by cords of hemp (in the case of letters of justice, and executory) or by red and yellow silk (in the case of letters of grace) that was looped through slits in the vellum of the document. Bulla is the name of this seal, because whether of wax, lead, or gold, the material making the seal had to be melted to soften it and take on an impression: Latin bullire, "to boil".

Since the late eighteenth century, the lead bulla has been replaced with a red ink stamp of Saints Peter and Paul with the reigning Pope's name encircling the picture, though very formal letters, e.g. the bull of Pope John XXIII convoking the Second Vatican Council, still receive the lead seal.

Original papal bulls exist in quantity only after the eleventh century onward when the transition from fragile papyrus to the more durable parchment was made. None survives in entirety from before 819. Some original leaden seals, however, still survive from as early as the 6th century.