Multi-stamped bulla (~1" diam.) formerly surrounding a dangling cord; unprovenanced Redondo Beach, California collection of antiquities
Bullae from antiquity appear in two distinct forms:
- A lump surrounding a dangling cord (as with much later wax bullae and papal bullsmade of lead rather than clay)
- A flat, disc-shaped lump pressed against a cord surrounding a folded document (such as papyrus or vellum)
In many cases, fingerprints of the person who made the impression remain visible near the border of the seal in the clay.
Gallery of bullae
- A bull of Pope Urban VIII. Note the lead seal attached to the cord.
Bronze Age Ireland
Papal bulls were originally issued by the pope for many kinds of communication of a public nature, but by the 13th century, papal bulls were only used for the most formal or solemn of occasions.
Since the 12th century, papal bulls have carried a lead seal with the heads of the apostles Saint Peter and Saint Paul on one side and the pope’s name on the other.
Modern scholars have retroactively used the term "bull" to describe any elaborate papal document issued in the form of a decree or privilege (solemn or simple), and to some less elaborate ones issued in the form of a letter. Popularly, the name is used for any papal document that contains a metal seal.
Papal bulls have been in use at least since the 6th century, but the term was not used until around the middle of the 13th century, and then only internally for unofficial administrative purposes. However, it had become official by the 15th century, when one of the offices of the Papal chancerywas named the "register of bulls" (registrum bullarum).
Papal bull of Pope Urban VIII, 1637, sealed with a leaden bulla.
The body of the text had no specific conventions for its formatting; it was often very simple in layout. The closing section consisted of a short datum, mentioning the place it was issued, the day of the month and the year of the pope's pontificate and signatures, near which was attached the seal.
For the most solemn bulls, the Pope would sign the document himself, in which case he used the formula Ego N. Catholicae Ecclesiae Episcopus (I, N., Bishop of the Catholic Church). Following the signature in this case would be an elaborate monogram, the signatures of any witnesses, and then the seal. Nowadays, a member of the Roman Curia signs the document on behalf of the Pope, usually the Cardinal Secretary of State, and thus the monogram is omitted.
The Pope issues Papal bulls through the various dicasteries of the Roman Curia. Pope Benedict XVI in 2008.
Lead Bulla (obverse and reverse) of Urban V, Pope 1362 to 1370
In 1535 the Florentine engraver Benvenuto Cellini was paid 50 scutes to recreate the metal matrix which would be used to impress the lead bulls of the Pope Paul III. Cellini retained definitive iconographic items like the faces of the two apostles, but he carved them with a much greater attention to detail and artistic sensibility than had previously been used on bullae. On the back of the seal he introduced several fleurs-de-lis, a heraldic symbol of the family from which Pope Paul III had come (i.e., the Farnese family).
Since the late 18th 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 11th 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.
The bull was the exclusive letter format from the Vatican until the 14th century, when the papal brief began to appear. The brief is the less formal form of papal communication and is authenticated with a wax impression (now a red ink impression) of the Ring of the Fisherman. There has never been an exact distinction of usage between a bull and a brief, but nowadays most letters, including encyclicals, are issued as briefs.
Printed text of Pope Leo X's Bull against the errors of Martin Luther, also known as Exsurge Domine, issued in June 1520