Secrets of Roman Silver Uncovered After 90 Years

New technology has enabled archaeologists from National Museums Scotland to digitally reveal the true size and scale of a Roman plate, parts of which were buried in a silver hoard at Traprain Law more than 1500 years ago.

February 2013 saw the launch of a digital reconstruction by National Museums Scotland of a very important Late Roman silver dish, fragments of which survive amongst the massive hoard of silver found in 1919 at Traprain Law, East Lothian. The digital reconstruction is part of a larger project made possible by the National Museums Scotland’s partnership with The Glenmorangie Company. This significant support has funded a 6-year research project and full-time academic research post devoted to better understanding the archaeology of Scotland during the early medieval period, AD300–900. The Glenmorangie Research Project began in 2008, and since then has received several awards in recognition of the innovative collaboration between the cultural and business sectors that lies behind it.

Reconstructing the past has been a central theme running throughout the project. A number of craft commissions have been made in order to bring to life important, but also fragmentary, archaeological remains. Each of these commissions has had research questions at its heart and has sought to enrich our understanding of how and why objects were made by working closely with people who continue traditional craft practices. Although the rationale was the same, reconstructing the Traprain Law silver dish marked something of a departure for the project, drawing as it did on the technical skills necessary to make a digital model rather than traditional craft practices. It is the first of three virtual projects that will be completed over the course of the coming year, all of which will feature in a temporary exhibition on the Glenmorangie Project’s findings at National Museums Scotland in Autumn 2013. In the meantime, it is profiled on the Glenmorangie Project’s webpage.

This digital commission shone a spotlight on one of Scotland’s most important archaeological finds – the biggest hoard of Roman ‘hacksilver’ from anywhere inside or outside the Empire. The hoard is very impressive in terms of its sheer scale and weight – it is made up of 22kg silver and over 250 individual pieces – and this it is easy to appreciate from its museum display. It is more challenging however to communicate the quality and prestige of the objects it contains, to show them as they would have been in their glory, and to tell the story, visually, of why these treasures were almost all hacked into fragments. This was the main reason for choosing one (particularly impressive) object from the hoard to be the subject of our reconstruction. Ongoing specialist examination of the contents of the hoard identified two fragments, both around 5cm in width, as pieces from the same bossed-rim dish. Parallels from elsewhere in Europe suggested it was likely to be a particularly impressive type of dish and perhaps a rival for the largest Roman dish ever known. For these reasons, these two fragments were chosen for digital reconstruction.

Relicarte was selected as the project partner and was tasked with creating the digital reconstruction. The combination of expertise in traditional arts and innovative new technologies and a desire to enhance access, appreciation and understanding of cultural heritage matched closely the aims of the Glenmorangie Project. The first stage in the project was to laser scan the two surviving dish fragments using a Faro Quantum arm and laser scanner. 3D laser scanners work by sending a laser beam all over the field of view. Whenever the laser beam hits a reflective surface, it is reflected into the direction of the scanner. This process results in a ‘point cloud’ making up a 3D replica of the two pieces. Step 2 involved software primarily used for the analysis of mechanical parts. The software was used to measure the curves on the two fragments, allowing a very accurate extrapolation of the dish’s rim and confirming its original diameter was an impressive 70cm. These two stages gave us an accurate base model of the dish which lacked any of the decorative detail.

Collaboration between Late Roman silver specialists and an archaeological illustrator, Marion O’Neil, enabled the dish’s decoration to be reconstructed. Parts of three decorative friezes from around rim survive, and their essentially repetitive nature meant that they could be completed with a high degree of confidence. Adjacent to the friezes are bust portraits and comparison with more complete dishes indicated that these friezes and busts would have been repeated right around the circumference of the dish. Work on similar tableware also indicated that the dish would have carried a large central decorative medallion, although no fragments of this survive in the hoard. A complete dish from the Late Roman Kaiseraugst hoard, Switzerland, provided a medallion design that most closely matched the content and style of the surviving Traprain Law rim decoration.

The reconstructed decorative frieze and central medallion were then incorporated onto the digital base model of the plain dish by Relicarte. Render effects were used to recreate the original appearance of the decoration – highlighted by a ring of gilding inlaid with niello, a black enamel-like inlay. The process involved many stages of drafting to finalise optimum surface finishes and the level of reflection in order to try and bring the dish to life.

The result is that it is possible for the first time to demonstrate just how big this dish would originally have been and what it would have looked like when newly made. It also provided an opportunity to tell both stories, or lives, of this dish and the Traprain Law hoard as a whole. The first life is that of the original objects, many of which are of the highest calibre of Roman silverware, valued for their sumptuous decoration and size. The second life is linked to economic crisis and changing values, a situation that saw precious objects like this dish hacked into pieces, no longer valued for its workmanship but purely as silver bullion. Finally, it provided an eye-catching means to begin to tell the story of how and why the dish arrived in southern Scotland, was gathered together with many other hacked up treasures, buried on the blustery summit of an Iron Age hill fort in the mid 5th century, and never retrieved.

To watch a video about the project, click here.