The conservation of the coffin

Introduction

A finely decorated Roman lead coffin, uncovered during Colchester Archaeological Trust (CAT) excavations in 2024, has gone on display this May following months of detailed investigation by CAT and conservation work by York Archaeology (YA). The coffin was discovered at the site of the former Essex County Hospital, currently being redeveloped for housing, where the remains of a woman were recovered. With its intricate motifs and unusually well-preserved structure, the coffin offers a rare and compelling glimpse into burial practices in Roman Britain.

Careful conservation treatment has ensured that researchers and visitors alike will be able to appreciate its striking details up close while safeguarding it for the future.

Object Background

This rectangular Roman lead coffin, complete with a fitted lid, is distinguished by its decorative design. Both the lid and the casket are adorned with scallop shell, rod and circular motifs, features often associated with Roman funerary symbolism. In particular, scallop shells were closely linked with beliefs surrounding the soul’s journey to the afterlife, symbolising the crossing of the ocean to the “Blessed Isles”, a mythical paradise in Roman thought. Prior to conservation, the coffin underwent micro-excavation and block lifting by the team at CAT, a meticulous process that allows archaeologists to preserve the fragile contents and contextual information during removal from the ground.

What makes this coffin particularly noteworthy is its condition. Unlike many comparable examples, which are often heavily distorted or fragmented due to centuries of compression in the burial environment, this piece survived with relatively minimal damage. Its decorative elements remained defined and legible, offering valuable insight into craftsmanship and aesthetic choices during the Roman period. Nevertheless, despite this exceptional level of preservation, the coffin still displayed a number of structural and corrosion-related issues resulting from long-term burial.

For the conservators involved, the project was also a particularly exciting opportunity. Roman lead coffins are rare finds, and the combination of surviving decoration, structural integrity and archaeological significance made this an especially rewarding object to work on.

Condition

Although the coffin retained much of its original form and decorative detail, it showed clear signs of stress and deterioration caused by burial conditions. Lead is exceptionally dense, but it is also remarkably soft and therefore prone to warping over time. The lid, for example, had developed a noticeable concave distortion and featured a substantial stress fracture near its centre, where part of the edge had partially detached. While much of the decorative surface survived intact, some edges had become brittle, resulting in localised fragmentation and loss.

The body of the coffin had also warped slightly but largely retained its original form, with the most significant damage occurring on one side near the head end, where part of the wall had collapsed during burial before later detaching. This fragment was especially fragile and displayed extensive active corrosion in the form of powdery white lead carbonate.

Other areas of concern included minor edge loss, surface abrasion, and structural strain, particularly at the head plate, which had begun to bend outward under its own weight. Inside the coffin, corrosion was more advanced than on the exterior, and traces of burial soil remained adhered in several areas. An unusual teardrop-shaped corrosion feature near the centre of the interior added a further point of interest, possibly relating to the burial contents or burial environment.

 

The conservation of archaeological lead objects presents particular challenges. Because lead is amphoteric, it reacts with both acids and alkalis. As corrosion develops, bulky corrosion products form beneath the original surface, forcing it outward and sometimes causing it to detach entirely. Unlike iron or copper artefacts, where corrosion layers can often be removed to reveal the original surface beneath, corrosion in lead can permanently displace or destroy that surface if deterioration becomes too advanced. Fortunately, in this case, active corrosion was relatively limited and the coffin’s decorative elements remained exceptionally well preserved.

Treatment

Conservation work focused on stabilising the coffin while improving the visibility of its decorative features. Treatment began with the careful removal of burial soil and active corrosion using soft brushes, specialist tools, a museum-grade vacuum, and, in some particularly delicate areas, a porcupine quill. The quill proved especially useful for working around fragile corrosion layers and decorative details, allowing deposits to be reduced with remarkable precision while minimising the risk of scratching or damaging the surviving lead surface.

Due to the toxicity of lead, full PPE was worn throughout treatment, including Tyvek suits, gloves, and full-face respirators to prevent inhalation and skin contact. While essential for safe handling, this protective equipment made conservation work physically demanding, particularly during long periods of close, highly detailed treatment requiring careful dexterity and concentration.

To remove finer residues, a solvent solution was applied to lift dust and dirt without introducing harmful moisture. Fragile areas, including cracks, weakened edges, and detached fragments, were consolidated using a conservation-grade acrylic resin to improve structural stability.

Where possible, detached fragments were reassembled and secured in their original positions. Fragments considered too heavy or unstable for safe reattachment were instead supported and stored within the coffin on custom-made mounts. A lighter consolidant layer was then applied across vulnerable areas to provide additional overall stability.

Finally, visually disrupted areas were carefully blended using microcrystalline wax, helping to restore a more unified appearance while remaining sympathetic to the object’s condition and history. The coffin and lid were then repacked using stable, inert materials, including Plastazote foam supports, to ensure their safe handling and storage.

 

The coffin is now on display at the Roman Circus Visitor Centre in Colchester in their temporary exhibition, ‘The Lexden Lady: From Burial to Biography’ from May 16th 2026 until May 2027. Further information about the individual, the coffin and the results of the analysis can be found on the Colchester Archaeological Trust exhibition page (https://catuk.org/roman-lead-coffin-exhibition/).