The Sutton Hoo Ship-Burial

What is a shipwreck?

The summer of 2019 marks the 80th anniversary of the excavations which led to one of the most spectacular Anglo-Saxon discoveries ever made, the ship-burial at Sutton Hoo in Suffolk. In August 1939 the contents of the burial were the subject of an inquest to determine whether or not they constituted treasure trove (they did not). (1) The astonishing finds discussed at the inquest on August 14 attracted a good deal of media attention over the ensuing fortnight, fascinating a public facing the imminent prospect of war.

Building on the previous year’s excavation works, archaeological excavations had resumed in May 1939. As Mound 1 was opened up, both landowner Edith Pretty and archaeologist Basil Brown were keen to see what they would discover. They may have had an inkling from the 1938 excavation, in which a lesser burial mound (Mound 2) had yielded ship rivets and a ‘boat shape’, but which had been robbed of associated grave goods in the past – but nothing could have prepared them for the find of a lifetime.

Within a few days a rivet was also discovered in Mound 1, and as more rivets emerged, it became clear that this was another ship-burial also containing an artefact assemblage which had defied earlier attempts at robbery.

Organic material, such as the hull timbers, had long since vanished in the acid soil. What was left was an intact ‘ghost impression’ of the ship, the disposition of the rivets bearing witness to its original clinker planking, and evenly spaced ridges of sand where the ribs had once been. In the same way the arrangement of personal artefacts, reflecting their natural position on or beside the body, revealed the original resting place of the deceased, whose remains had been similarly consumed by the soil.

Historic 1939 B&W film still showing archaeologists at work within the 'ship-shape' with the ship structure visible in the sand, and all the rivets still in situ.
The ‘ghost impression’ of the buried ship as revealed in 1939. Still from a film made by H. J. Phillips, brother of Charles Phillips: permission for unlimited use granted by son William Phillips and grandson Jeremy Gilbert.

It was a very special ship with a very special ‘passenger’ and ‘cargo’, a high-status male burial containing an extremely diverse, rich, and finely-wrought, assemblage of artefacts from the Anglo-Saxon world and beyond. Since that summer of 1939 this assemblage has been assigned to the early 7th century and has been interpreted as the grave of Raedwald, King of East Anglia, who was noted in a 9th century chronicle as bretwalda with some form of overlordship over other Anglo-Saxon kings.

If the ship was deliberately deposited, hauled up from the nearby River Deben, ten miles from the sea, as the river meanders, and intended for preservation by burial, rather than destruction, why are we making it the subject of a Wreck of the Week?

This article weaves together the diversity of our wreck heritage, the features the Sutton Hoo ship-burial shares with more conventional wreck archaeology, and the context of war, since the find also foreshadows the 80th anniversary of the outbreak of the Second World War.

The key driver for interpreting the Sutton Hoo burial as a ‘wreck’ in one sense is because of the very disappearance of the ship itself. By contrast, a number of Viking Age ship-burials in Norway, relatively close in date, cultural milieu and deposit context, have been well-preserved (Oseberg, c.820, discovered 1903-4; Gokstad, c.890, found 1879; and Tune, c.900-910, excavated 1867). Unlike these examples, the ship at the centre of the Sutton Hoo burial has been ‘wrecked’ literally by the sands of time, namely its 1,300 years from deposit to discovery within a mound of sandy and acidic soil.

It is certainly an unusual ‘wrecking’ process, and despite its proximity to the river, one well outside a waterborne context, which makes it all the more unusual. The nearest parallels in the British Isles lie outside an English context, for example the Viking Age ship-burials at Ardnamurchan, Scotland, and Balladoole on the Isle of Man, in both of which the timbers have also leached away.

Also exceptional, from a maritime point of view, is the way the mound has acted as ‘destroyer’ rather than ‘preserver’ of the vessel: unlike the grave mounds built on land by human hands, wreck mounds tend to form by a natural accretion process, helping to preserve timbers and other organic contents within an anaerobic environment that prevents or delays decay (as can be seen on artefacts from the designated Rooswijk of 1740, for example).

Wreck processes in the inter-tidal zone and in or immediately beside rivers often provide visible and accessible illustrations of underwater wreck processes. For example, the scour pit around the wreck of the Amsterdam (1749, also designated) in the inter-tidal zone at Bulverhythe demonstrates on land how sunken vessels can ‘scour out’ a pit for themselves by their own motion against that of the tides and currents of the surrounding water column.

In the same vein, the two wrecks at the designated Salcombe Cannon site (identified from their associated assemblages as Bronze Age and 17th century respectively) demonstrate within the marine zone how the geology of the site environment itself, as at Sutton Hoo, can act as a medium of destruction and decay. A dynamic environment, full of rocky gullies, has eroded any remaining timbers, although those same gullies have sheltered and preserved the cargo scatters.

Elsewhere a cargo may demonstrate the presence of a wreck without an associated hull which may either have degraded or remains to be discovered, such as the Roman-era Pudding Pan Wreck in the Thames Estuary, which has yielded quantities of Samian ware over the centuries. In retaining its rich assemblage without its originating vessel, the Sutton Hoo burial has a point of contact with such wreck sites.

In some ways, the ‘wreck process’ associated with the lesser-known Mound 2 ship was similar to that of Mound 1, with the same acid soil working on its timbers. However, there were other intervening events between deposit and discovery which contributed to the loss not only of the vessel but also of its context. Unlike Mound 2, the rivets were scattered and no longer bore witness to the original vessel structure, having been disturbed by earlier grave-robbing activity. Essentially this activity was a historic example of what we would today designate a heritage crime.

Such problems could be exacerbated by the archaeological standards prevailing at the time of discovery. We have covered this before in our earlier post on Anglo-Saxon wrecks in the Manchester Ship Canal but there were others: as far back as 1862 an Anglo-Saxon ship-burial was discovered at Snape, also in Suffolk. Although the site was recorded and published, and some physical evidence survives in the form of the iron rivets which were also found on that site, our understanding of this vessel remains incomplete. Between the site’s original discovery and further archaeological exploration in the 20th century, the landscape was much altered by ploughing with the loss of detail and context. This particular case highlights the importance of careful survey and recording, which guards against knowledge and/or site loss, and acts as ‘preservation by record’.

Four incomplete iron rivets seen against a white background.
Iron rivets from the Snape ship-burial, on display at Aldeburgh Moot Hall Museum. User:Midnightblueowl [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)]
In 1970, another Anglo-Saxon vessel, a clinker-built boat dated to the late 9th century, was discovered at Graveney, Kent, during excavations for a drainage channel in the local marshland. It has been interpreted as a sea-going vessel, abandoned in the marshes approximately a kilometre from the sea, and thus from a different context entirely to a ship-burial.

Such loss through abandonment appears to be typical in the records of many boats discovered archaeologically in the 19th century and early 20th centuries and attributed to the Anglo-Saxon or Viking periods or even earlier. It is plausible that many such vessels were initially laid up over a period of time, with the intention of being brought back into use again (not dissimilar in some ways to the point with which we started, the determination of treasure trove!).

Such vessels, whether as logboats or more formally built with worked timbers, then passed completely out of use, through obsolescence, the economics of repair, or perhaps simply on the death of their original owners. These hulks are analogous to the many Thames barges which worked the river up until the mid 20th century and which now lie rotting on the shores of Essex and Kent. The Sutton Hoo mound likewise looks across the River Deben to two modern hulk assemblages on the opposite bank at Ferry Cliff and Sun Wharf. These hulks have been either forgotten or deliberately abandoned and the long slow process of decay has transformed these vessels into ‘wrecks’, in the sense of vessels  no longer capable of their original navigational function.

Historic sepia photograph of two pine tree tops looking down below to a river scene, with the adjoining bank visible below the trees and the opposite bank in the distance, across the middle of the image.
A late 19th-early 20th century view past pine trees across the River Deben at Woodbridge. The Sutton Hoo ship burial was discovered close to this spot in 1939. Source: Historic England Archive

The relative ease of logboat excavation in the Victorian or Edwardian periods means that these have been particularly prone to being lost post-excavation, because of the archaeological recording and storage standards then prevailing. It is arguable that their discovery can be seen as the final stage of a long-drawn-out ‘wreck process’ regardless of the original owners’ intentions or context of deposit, a fate shared with the subject of a recent post, the Ship under the Power Station.

The most dramatic example of such a fate was a Bronze Age boat discovered in 1886, carefully preserved by Victorian standards and put on display in Hull and East Riding Museum. It was finally destroyed or ‘wrecked’ in possibly the most extreme example of a multi-phase wreck process recorded in England – during a Second World War bombing raid which severely damaged the museum itself in 1943.

It is extraordinary to think that the Hull Bronze Age boat not only shares a multi-phase loss process with many other craft of different types and eras, but also has something in common with vessels of 1940s construction sunk in coastal waters by the 1940s means of air attack.

By any standards the Sutton Hoo ship-burial was an extraordinary archaeological discovery. Although not unknown in a national or international context, ship-burials remain rare finds, while the remarkable grave goods within have done much to inform our understanding of the Anglo-Saxon period. Despite more recent Anglo-Saxon discoveries of comparable magnificence such as the Prittlewell Princely Burial or the Staffordshire Hoard, the Sutton Hoo ship-burial retains its significance and glamour.

One of the ways in which the importance of Sutton Hoo was recognised was immediate: the site was Scheduled as an Ancient Monument in November 1939, two months into the war, and the assemblage would spend the war in storage, along with many other national treasures.

Other Anglo-Saxon boats have also been discovered before and since, but to date there have been no known Anglo-Saxon finds in the marine zone, although the Anglo-Saxon Chronicle records a few wreck events. The surviving written record, however, is pitifully thin by comparison to the number of wrecks which must in reality have occurred, simply by the very nature of seaborne traffic (touched on in a previous post, 1066 and All That). It is a reminder that the goods in the Sutton Hoo ship-burial, such as the Frankish coins and Byzantine bucket, were all the more valuable for safely arriving following a sea voyage.

The Sutton Hoo ship-burial bridges ‘marine’ and ‘terrestrial’ archaeology, in which patterns shared with wreck archaeology can be clearly seen. Despite some parallels such as at Balladoole, it is also the only ‘wreck’ we know of in an English context discovered by clear evidence of what was once there, rather than a simple absence of surviving ship structure, and thus so far unique within England’s diverse wreck heritage.

Had the burial not been discovered in the summer of 1939, just before Britain went to war, perhaps much of its context would have been compromised. Over the next few years Mound 1 would be subjected to intrusive military activity which has left its scars on the landscape, and which could so easily have damaged or destroyed the ‘negative impression’ of the ship.

This post also paves the way for our upcoming War Diary for the Second World War, commencing in September 2019.

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(1)  It was determined that they were clearly buried as part of a highly public funeral rite, with no intention of recovery, so that ownership passed to the finder (rather than hidden in secrecy with the intention of later recovery, in which case they would have been deemed treasure trove and thus assigned to Crown ownership).

 

On the cleaning of metal finds from the London and the Rooswijk

I am pleased to introduce this week as my guest blogger Elisabeth Kuiper, who has just completed an internship with Historic England. She tells us about her recent experiences in the conservation of metal artefacts from two designated shipwrecks:

Most historic ships are full of iron: think of nails and bolts in all sizes, ship equipment, rigging elements, chains, anchors, iron cannons and all sorts of different tools used on the ship. This iron, in the unfortunate event of ending up on the seabed, usually grows very bulky corrosion products eventually covering the original surface of an object. Iron objects from a maritime archaeological context are thus very often found as mysterious and unrecognisable lumps, known as concretion, as they have become covered by a thick formless mass of corrosion which can incorporate sediment and shells, and also different objects in the vicinity. In order to understand the concretion and what is, or used to be, inside it, the conservator uses X-radiography. X-radiography gives the opportunity to investigate the concretion without damaging it: dense areas or voids will show up on the image and so may be able to tell what has caused the concretion.

Once it is clear that the concretion may hold something worth investigating further, the conservator will start off mechanically cleaning it. Corrosion products are taken off layer by layer until the original surface of the object is found. In the process of cleaning other artefacts which may not have been seen previously on the x-radiograph, can be found trapped in the corrosion layers, for example, pieces of glass, ceramics or small metal objects.

Unlike any other metal, in an advanced stage in the corrosion process the iron of the original object can have migrated entirely to its corrosion layers, and we are left with a void that retains the shape of the object precisely. If needed, these voids can be filled with a silicone rubber or casting resin. Once all concretion is removed the conservator is left with a perfect cast of the object that would otherwise be lost forever.

I am a Professional Doctorate student in conservation and restoration at the University of Amsterdam, specialising in metal conservation, and have been working at Historic England on an archaeological conservation work placement for the past months. My main focus during my time at Historic England was the remedial and investigative conservation of finds from the protected wreck sites of the Rooswijk and the London. The London was a Royal Navy warship that went down in the 1665 after an accidental explosion aboard the ship, and many different objects were recovered during the salvage operations between 2014 and 2016.

The Rooswijk was a Dutch East Indiaman that ran aground on the Goodwin Sands, off Kent, in the winter of 1740. The shipwreck was partly excavated and recorded in the summer of 2017, after which the finds were taken to Historic England storage facilities for assessment, analysis and conservation.

During my time at Historic England I have worked on quite a diverse range of finds from both wreck sites, but what they all had in common was the various amounts of iron corrosion on the object’s surface. As previously mentioned, this is quite typical for maritime archaeological artefacts, which (as we will see) can even be totally enveloped in iron corrosion. A few of the more straightforward objects I have worked on were from the London:

Hammer laid vertically, showing concretion at the head, with scale marker and label to left.           x-ray of hammer, laid diagonally with head at top left, concretion showing up as white around the head.           Hammer laid vertically showing head with concretion removed, scale rule and label to left

Figure 1. Different stages of conservation process on hammer from the London: before treatment (left), x-radiograph (middle) and after cleaning treatment (right) © Historic England

In Figure 1 above we see a hammer, with iron corrosion products covering the original surface. The hammer was cleaned using a pneumatic tool called an air-scribe, which can be seen as a small jackhammer. It is ideal for removing concrete-like iron corrosion products, with the x-radiograph was used as a guide during the cleaning. When looked at carefully, the x-radiograph clearly shows the typical lamellar structure of corroded wrought iron. Wrought iron is essentially pure iron containing less than 0.2% carbon by weight. The main compositional variation is in the presence of slag inclusions. When worked these slag inclusions are forced out in the direction of working. On the seabed not only does the metal surface corrode, but also the walls of the slag inclusions, as seawater is able to penetrate deep into the metal. As a result the metal shows a wood grain-like appearance, typical of wrought iron recovered from shipwrecks.

The same became clearly visible as corrosion was cleaned away on a rigging element called a deadeye:

Deadeye with rust-coloured concreted surface, label and scale rule to left    Deadeye following removal of concretion, showing its shape and dark colour more clearly. Scale rule below the object.

Figure 2. Deadeye from the London, before (left) and and after (right) cleaning © Historic England

Up to now I have discussed corroded iron objects. Surprisingly, it’s not only objects made from iron that can become covered by a thick iron concretion crust. As we will see in the next images, copper alloy objects can also become unrecognisably changed due to maritime corrosion processes:

Pan body showing rust-coloured concretion, particularly around the edges, with scale rule and yellow archaeological tag below.  Pan after cleaning, with concretion removed, showing a darker metal colour and some discolouration. Scale rule and yellow tag below.

Figure 3. Copper alloy object from the Rooswijk, before (left) and after (right) cleaning © Historic England

The artefact shown here is a copper-zinc alloy object, presumably a pan of some sort. Probably it will have had a handle that was riveted to the pan itself. These rivets were already visible on the x-radiograph, but were uncovered during cleaning.

Detail of 4 rivets on rim of pan, with centimetre scale

Figure 4. Detail of rivets on rim of pan after treatment (above) with corresponding features visible on x-radiograph prior to treatment (below) © Historic England

x ray of whole pan, with 4 rivets showing up as small white round features at top

Cleaning of maritime archaeological finds can be rewarding and satisfying work, in the sense that the disfiguring corrosion layers are slowly removed to reveal a recognisable object once more. Sometimes these objects can even be in quite a good condition. The cleaning of concreted artefacts can almost be seen as a mini-excavation. To illustrate this, I will show one last treatment on a concretion, which furthermore posed quite a challenge:

Irregular lump of concretion with shells and other material embedded, scale rule and yellow number tag at bottom

Figure 5. Concretion from the Rooswijk before cleaning treatment © Historic England

Fig 6

Figure 6. X-radiograph of concretion in Fig 5 before cleaning treatment, where rings, a coin and many beads (lighter areas) as well as different sizes of nails (darker areas) become apparent © Historic England

In this case, cleaning of the concretion was more of a challenge because of the mixture of elements and materials in it. The concretion consists of approximately 17 copper alloy rings, 1 silver coin and over 400 tiny glass beads. What was left of the iron (mostly nails and/or small bars), as explained earlier, were just voids. The concretion itself proved to be a harder material than the glass beads, which tended to shatter when the air-scribe came close. Mechanical means thus did not seem to suffice to remove the beads from the concretion, but a chemical treatment would be difficult to select, as the other metals would react to the chemicals as well as the iron concretion. As a first step, the concretion was mechanically cleaned until beads and artefacts, including voids, started appearing:

Detail of artefacts in concretion revealed after cleaning, such as rings and yellow beads

 

 

Figure 7. Reverse side of the concretion from the Rooswijk, with detail photo above left; the complete artefact below right, after initial mechanical cleaning; notice the yellow beads, copper alloy rings and coin © Historic England

The same lump as in figure 6 following initial cleaning, with rings, beads and coins now visible. Yellow tag on left, scale rule on object

 

 

 

 

 

 

Detail of obverse side of concretion, with rings visible on the left: scale rule on object on the right, yellow tag below

Figure 8. Obverse side concretion from the Rooswijk after initial mechanical cleaning; notice the voids in the shape of a nail (on the right) and small bar-like shapes © Historic England

Because initial research proved the voids to be ‘just nails’, the decision was made to record them as best as possible, but then to sacrifice them in the bigger scheme of things. This way, the concretion could be broken apart in smaller pieces that offered the opportunity to treat them separately from the coin and rings. This work is still ongoing and consists of a combination of mechanical and chemical treatments in order to gently dislodge all the different objects from the concretion for further study.

Thank you to Elisabeth for sharing the problems and processes of conserving concreted objects from the London and the Rooswijk, and which complement previous blogs by our conservators: see links below. We hope she has enjoyed her time with us and wish her all the best for the future.

For more archaeological conservation stories on the varied artefacts from the London:

The London: A conservator’s tool-kit

Conservation of artefacts from the London

How to do . . . archaeological conservation

Glossary:

lamellar: