There are many fascinating aspects to St Aidan’s church; spiritual, cultural and architectural. One unique attraction is the crypt which lies below the two easternmost bays of the chancel. It was built in 1230 and is an atmospheric space that displays the skills of the medieval stone mason and also provides an astounding link to our very distant past.
On entering the church grounds the entrance to the crypt is concealed from view. Moving closer to the south wall of the chancel reveals a sunken passage. Looking into this passage you can see the footings of the chancel wall piers and also a square-headed doorway. This opening was formed when the chancel was constructed although only the lower section has the original stone surround. Stepping over the threshold places you on a new viewing platform that will transport you from the 21st century back to the 13th century and beyond. On plan, the crypt is almost square but you cannot see it straight away as there is a dividing wall running along the east/west axis which divides it into two unequal parts.
Both parts are of great interest for completely different reasons. The larger southern chamber, which you enter first, has an unusual vaulted ceiling above your head and bodies under your feet. The northern chamber, which you can glimpse through a small opening in the dividing wall opposite the entrance steps, is now the final resting place of 110 people who lived in Bamburgh 1,400 years ago. You can read more about the ossuary and the history of its inhabitants here.
The vaulted ceiling in the southern chamber is formed in two bays. One way to visualise this part of the crypt is to imagine standing in the centre of the stone floor. Directly above your head, running between the north and south walls is a semi-circular transverse stone rib. Where it meets the walls it is supported on a simple stone corbel. This central arch is common to both vaulted bays. From the same position, looking towards the east wall, you see two lancet windows.
On the left and right ends of this wall there are another two stone corbels about chest height. Springing from each is a diagonal stone rib. As these ribs arc towards you they cross at the mid-point of the vault and then continue until they land on the same corbels that support the transverse rib.
There is one further addition to the crypt vaults which makes them rather unusual.Normally there would be four panels formed by the transverse and diagonal ribs but here there are five. This is achieved by the addition of a further axial stone rib running from a corbel located between the two lancet windows to the crossing point of the diagonal arches. It isn’t clear why this rib was introduced but it does provide space for an aesthetically pleasing pointed arch framing above the head of the windows.
If you were to turn around 180 degrees you would see exactly the same rib structure forming the western vault.
Looking up, still in your position under the transverse arch, you will see that the infill panels between the ribs are formed from individual stones. How do they stay in place? Medieval stone masons did not have the convenience of modern building methods we take for granted, such as reinforced concrete. Instead, they relied on a deep understanding of geometry and the transfer of structural loads from one element to another using the sequence of construction to ensure stability. Even with no apparent support, the stone infill will not fall on your head.
In addition to the two lancet windows in the east wall there is one in the south wall. They all have a triple step to the internal sill but only the eastern pair have attractive shouldered arches starting, rather unusually, two-thirds up the jamb rather than directly below the lintel.
Beneath the lancet window in the south wall is a piscina, with a small trefoiled arch and a moulded bowl.
A piscina was usually placed near an alter so that liquids from any religious ritual could be disposed of in an appropriate way.
There are other less obvious features in the south chamber that could find their way into a Dan Brown novel. Why are there three small rectangular recesses in the north wall, two in the western bay and one in the eastern? Directly above the easternmost recess is a block with a pattern of radial lines. Is this some form of mass dial and if it is, why is it inside where no form of direct sunlight can reach it? If you search the other walls you will find further marks and crosses. They could be symbols or medieval graffiti.
Today, access to the northern chamber is provided through the west end of the dividing wall, opposite the main doorway into the crypt. Here there is a small opening about one third the height of a normal door. The size and form of the old stone sill suggests that at one time the opening was even narrower.
This restricted access was not the only way to enter this part of the crypt. There is evidence that one, and perhaps two, other entrances to the north chamber existed. In 1837, as part of the inspection of the ‘Death House’; as it was known, the floor of the chancel was opened to reveal a flight of stone steps leading through the original wall of the crypt to the northern chamber. Intriguingly the inspection report also records that probings under and near the east window:
‘…seem to favour the tradition current at Bamburgh that there was a subterranean passage from the religious house directly opposite to the east end of the chancel’.
Once inside the northern chamber of the crypt there are two very obvious architectural features: the barrel vault roof and the single lancet window. The vault runs the full length of the chamber. It is built with rough stone and springs from a continuous chamfered moulding running along both long walls. We know from the 1837 inspection that the stone vault was finished with plaster. The single lancet window is similar to those in the east wall of the southern chamber but has a simpler lintel and surround.
The floor is only compacted earth but what stands on it gives this space a poignant spiritual quality. A simple metal frame holds 110 zinc ossuary boxes. Each one contains the bones of an early Christian, exhumed from the nearby Bowl Hole cemetery. Radiocarbon and artifactual dating place the cemetery in the mid-7th to early 9th centuries.
The original purpose of most crypts built in the 13th century was to provide safe storage for ancient relics and a suitable place for their presentation. Today the crypt of St Aidan’s protects something equally precious and in doing so completes a religious circle. It is astonishing to think that some of the people whose remains lie in the northern chamber may have actually listened to St Aidan before he died in 651AD or attended services in the original wooden church, which was built in 635AD on the very spot where they now rest.
Robert McKibbin – architect and Bamburgh Bones volunteer