A Medieval Bishop's Palace in Ancrum?

Medieval pottery and an iron swivel ringOver two weeks in September 2019, AOC supported Ancrum & District Heritage Society in running a programme of excavation at Mantle Walls, the supposed site of a medieval Bishop’s Palace.

It is known from documentary sources that William de Bondington, Bishop of Glasgow from 1232/33 until his death in 1258, had a palace at Ancrum, famed for its gardens. King Alexander II and his retinue signed three charters there in 1236.

Geophysical survey and keyhole excavation by Glasgow University (2011-2012) had provided evidence for a wealth of anomalies and at least one high status medieval stone building, in the form of ashlar stonework and a blocked-up chamfered doorway.

This season’s excavation focused on re-opening and extending the trenches from previous works, with a view to establishing whether evidence could be sought to confirm the sites status’ as a Bishop’s Palace.

Trench 1 was opened over the previously identified high status medieval stone building and extended further to the south to reveal more of the interior of the structure. The excavation revealed a deep stratigraphy of collapse and backfill, covering an internal deposit rich in animal bone and cereal grain. Underlying this internal deposit, a pit had been cut into the natural subsoil which contained animal and fish bones as well as a single sherd of pottery. The building itself had been terraced into the slope of the hill and was therefore partly subterranean, possibly constituting a cellar or storehouse. The blocked up chamfered doorway represents a later phase of remodeling to the building.

Trench 2 was opened over the site of another trench excavated previously by Glasgow University, in which a deep deposit of rubble and soil mixed with medieval and post medieval ceramics was uncovered. This season’s trench was extended to both the East and South to investigate further anomalies from the geophysical survey.

Images of the trenches at Mantle Walls

Left and centre: trench 1 and the end of excavations. Drone shot courtesy of Richard Strathie, ADHS. Right: wall with buttress in trench 2

Trench 2 revealed the remains of substantial stone built walls with possible evidence of buttressing (below, right), which represent several phases of construction in the life of the building. Evidence in the form of a possible trough feature and an iron pivot-ring (above, bottom) suggest the presence of a courtyard, and a set of stone steps were uncovered which lead up into the interior of a building, which once likely held a wooden floor. A substantial medieval pottery assemblage was also uncovered (a selection shown above, top), as were several large pieces of carved masonry which attest to the high status adornment of the building.

Two pieces of carved masonry, and a chamfered doorway

Left, centre: carved masonry. Right: chamfered doorway

A ground penetrating radar survey was also carried out as part of the works which revealed further anomalies, suggesting that the complex of buildings present onsite is substantial.

We look forward to learning more about the site through the post-excavation analysis programme that is currently underway.