The term seal usually refers to the impression produced when an engraved metal die or ‘matrix’ has been pressed into some soft material such as wax. Seal impressions could also be produced in malleable metals, like gold or silver, which are more durable than wax. Another practice, exemplified by the papacy, was to use a seal of lead – the bulla – which featured images and text on both sides somewhat like a coin. However, unlike wax, which could be stuck on the document itself, the bulla had to be attached to a document with string.

Medieval seals were mainly used as means of authenticating documents. They were visible and tangible objects that symbolised the author’s will. A seal affixed to a document validated the text and converted it into a formal legal instrument. A seal acted as a physical extension of its owner, and could therefore endow a document with intrinsic value, representing the presence of the author. Aside from authenticating documents, sealing could also establish ownership, signify commitment and represent authority. These small objects were more than symbols of authority or legality; they could also act as expressions identity. Within the space circled by their legends, medieval seals displayed a number of motifs & designs that expressed their owner’s self-perceptions. Medieval seals could embody and convey both personal and institutional identity.

As well as being religious institutions Military Orders – such as Templars, Hospitallers (Order of St John), Teutonic Knights – were also commercial organisations, preoccupied with their survival and maximising financial rewards. The Orders were also largely reliant on patronage and donations to their cause. It was therefore in their interests to put across a positive image of themselves and their activities. One of the ways in which an Order could project its image was by the use of seals. Seals could effectively act as an emblem or logo. It was important that seals fitted in with how a religious order perceived itself and with how it wanted to be viewed by the outside world. Although fewer people would have been aware of seal imagery than representations on coins for example, the impact seals would have had should not be underestimated. Patrons and tenants would have been aware of them on land grants and transfers, and indulgences and letters of confraternity would have had a wide circulation across the social spectrum. Given the limitations of mass communication in the middle ages, a seal would probably have been an effective method of conveying this message in a visual and instantly recognisable form. A seal could act as a public statement of identity.

The Grand Master’s seal – or leaden bulla – was the oldest seal of the Order of St John, and initially also used as the Order’s Great Seal. The Master’s bulla remained in use, with some modifications in design, from the twelfth century down to the loss of Malta in 1798. The seals were about 1&1/2 inches in diameter, and were attached to documents by cords of twisted, usually yellow, silk. Until the introduction of the Conventual bulla by Grand Master Nicholas de Lorgne in 1278, the Master’s seal was attached to all official documents of any importance. The general design of the seal featured, on the obverse, the Grand Master kneeling in prayer before the patriarchal cross. This image was usually accompanied with the sacred letters alpha and omega, which referenced the Second Coming of Christ. The central image was surrounded by a legend with the Master’s name followed by the official designation CVSTOS – guardian or keeper of the Order. The reverse of the seal depicted a dead body lying before a tabernacle. The surrounding legend seems to identify the institution as HOSPITALIS IHERVSALEM. One interpretation is that the image is a representation of a patient in the Hospital in Jerusalem. As the person outlined is evidently deceased, the seal may be portraying the ceremonial care of the dead and of their souls rather than medical care of the sick.

Seals such as those of the Grand Masters, depicting the Master in prayer before a cross, were known as seals of devotion, participating in a Christological narrative. The cross represented the crucifixion, while the letters alpha and omega referred to the Last Judgement. It is also possible to interpret the dead body as that of Christ, and the tabernacle as the Church of the Holy Sepulchre.

The seal of Grand Master Garin de Montaigu (1207-28) was the last to use simple designation of CVSTOS (guardian) on the legend. The inscription was modified with word FRATER (brother) appearing before the Grand Master’s name. It is interesting that the Master’s name is in the nominative (or subject) case in Latin. Seal legends usually referred to the sealer in the genitive case, indicating their possession of the seal. The legend in early Hospitaller seals reinforced the Grand Master’s personal presence in the seal. It is possible that the design of the seal sought to involve the Grand Master himself in the Christological dialogue. The design of the seal could be interpreted as the death, entombment and resurrection of Christ. But it could also be intended as a representation of the life of the Grand Master, who, as indicated on the seal, lived as a guardian of the Order and died under its care.

However, in later seals, starting with the bulla of Grand Master Raymond Berenger (1365-74), the design was modified and the inscription changed. The legend became more specific with the title CVSTOS followed by the word PAVPERVM (of the poor). The name of the Grand Master was now in the genitive (or possessive) case, which was more common on seals.

No representation of their military activities appears on the Hospitaller seal. In contrast, the seal of the Grand Master of the Knights Templar, depicted two knights on one horse on one side of the seal and the Dome of the Rock in Jerusalem on the other. The seal represented both the religious and military roles of the Templar Order. While the basic design of the Hospitaller Grand Master’s seal appears to have been in existence before the Hospitaller’s militarisation, it is interesting that they chose not to update the design to reflect the change in the Order’s activities. The period in which the militarisation occurred seems to have been a difficult one for the Hospitaller Order. While it appears the Order was involved in some military activities by the 1160s, there was unease about the relationship between warfare and caring for the sick. The Order eventually solved the problem of its apparently disparate roles by attempting to link them more closely together. The Hospitaller’s military activities were presented as acts of mercy, perhaps an extension of the care and protection of poor pilgrims, with a decree stating that even the warhorses of the knights should be at the disposal of the sick if they needed transportation. However, it seems the Grand Masters chose to maintain the focus on – and therefore represent – the Order’s charitable and religious functions on their seals. Even after the Order became militarised their role as ‘Hospitallers’ was still seen an important part of their vocation. The seals of the Grand Masters say much about the image the Order wished to portray about themselves.