Our excavations at Sheffield Castle as part of Sheffield City Council’s Castlegate regeneration project have unearthed the first surviving examples of 17th-century Civil War defensive stakes known as an 'abatis'. They were used to protect the castle from attack during the Civil War.
Four stakes around 1-metre in length were carefully excavated from the moat. It was clear to the dig team that these were not merely fallen branches but worked timbers that had been shaped into a point and driven into the partially silted-up moat. Analysis so far suggests that they could have formed part of an ‘abatis’. Abatises are a well-known method of fortification, constructed from large tree branches with the ends and side branches cut down and sharpened to points, but this is the first time the wood from an abatis has been recovered. Archaeologists usually find only the shadow of where the wood had once been. The stakes would have been arranged chaotically and dug into the ground to form a vicious barrier in strategic locations. This barrier was designed to impede attackers and hold them at bay for longer, creating a ‘killing zone’ where defenders of the castle could dispatch them. At Sheffield Castle, the abatis was placed in front of the imposing medieval gatehouse, a crucial point in the castle’s structure.
Ashley Tuck, the archaeologist leading the dig on behalf of Wessex Archaeology, said:
“So often we are told about Civil War defences like abatises being used at historic properties across the country, but usually there is little to see of these important features. To be able to hold the very wood to which the defenders of Sheffield Castle trusted their lives is extraordinary. Records show that the castle finally succumbed to Parliamentarian forces after a 10-day siege in August 1644. We know that these timbers and the abatis they formed were ultimately unsuccessful in protecting the castle from being destroyed, but they paint a picture of the brutalities of the war and add to our understanding of this turbulent period in Sheffield’s past.”
It is highly unusual to find these wooden stakes intact as they typically decay over time or were destroyed after use. These timbers were quickly buried after the siege, during the slighting of the castle. This meant they were preserved within the foul-smelling remains of the six-metre-deep rock-cut moat. The waterlogged ground provided the ideal conditions for their preservation, meaning that they survived for almost 400 years to reveal further insight into this dramatic period in Sheffield’s fascinating past.
Further analysis of marks and details on them could hint at the speed the defenders had to work at to prepare the castle for attack. They are Ash and Elm, and both tree species are native to the British Isles. The branches were crudely prepared for their task, and it’s possible to see pieces of bark left on the trunks, rough edges and visible axe marks which suggest the people making this structure were working quickly, possibly with the knowledge that an attack wasn’t far away.
The timbers are currently being carefully conserved at York Archaeology.
The castle has long been hailed as the ‘birthplace’ of Sheffield and stood for hundreds of years as an imposing symbol of power. After the Parliamentarian victory at the castle, it was slighted and left in ruins as a symbol of their victory and the seismic shift in power.
The project is part-funded by the UK Government and by the South Yorkshire Mayoral Combined Authority. The excavation, overseen by construction engineering specialists, Aureos (formally Keltbray Infrastructure Services Limited) is the first large-scale professional excavation ever undertaken on the site. The discoveries made during this project have also led to the Sheffield Castle dig being awarded Rescue Project of the Year at the Current Archaeology Awards 2025 at a ceremony in London on Saturday 1st March 2025.
As well as exposed remains of the Castle, the new park will offer visitors sight of the river Sheaf for the first time since 1911, an event space, as well as meadow planting and trees and a replica of the moat as a wetland.
To keep up to date with the dig follow the action on social media @wessexarch #SheffieldCastle.