File:Medieval, Incomplete papal bulla of Pope Adrian IV (FindID 618216).jpg

English: An incomplete lead alloy papal bulla, probably of Pope Adrian IV (c. AD 1100 to AD 1159), probably dating to the period AD 1154 to AD 1159, when he held the papacy.

The obverse bears an inscription of ADRI/ANVS/PPIIII, split into three lines, identifying it as a bulla of Pope Adrian IV. The pelleted border has been worn away.

The reverse depicts St. Paul is on the left of the seal looking right, depicted with a long pointed beard. 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. Across the top of the obverse, the inscription reads SPA SPE (an abbreviation of St Paul and St Peter. The pellet border has been worn away. An almost vertical rip is present, where the cord has pulled through the lead seal.

The bulla is 33.3 mm in length, 40.5 mm wide and 5.5 mm thick. It weighs 40.5 g.

It is a light to mid grey colour, with an even surface patina. Abrasion, caused by movement whilst within the plough soil, has resulted in a loss of some of the original surface detail.

The papal bulla is a formal seal of office used by the Popes to stamp and authenticate documents produced by the papal curia. Dr Tim Pestell has commented on other records: "Papal bulls came as two basic types, according to the contents of the document: Tituli, or "Letters of Grace", essentially granted or confirmed rights, conferred benefices or promulgated statutes. They generally had their lead bullae attached with cords of silk. Mandamenta, or "Letters of Justice" were mandates that conveyed papal orders, prohibitions or injunctions, and had their bullae attached by hemp threads".