An aerial view of Windsor Castle with its shell keep (called "The Round Tower") prominent on its motte inside the middle ward (middle bailey)
A shell keep is a style of medieval fortification, best described as a stone structure circling the top of a motte.
In English castle morphology, shell keeps are perceived as the successors to motte-and-bailey castles, with the wooden fence around the top of the motte replaced by a stone wall. Castle engineers during the Norman period did not trust the motte to support the enormous weight of a stone keep. A common solution to this problem was to replace the palisade with a stone wall and then build wooden buildings backing onto the inside of the wall. This construction was lighter than a keep and prevented the walls from being undermined, meaning they could be thinner and lighter.
A gazetteer compiled by archaeologist Robert Higham counted 21 shell keeps in England and Wales.[1] Examples include the Round Tower at Windsor Castle[2][3] and the majority were built in the 11th and 12th centuries.[4]
Surviving English examples of shell keeps include:
Arundel, West Sussex (re-modelled post-medieval)
Berkhampstead, Hertfordshire
Carisbrooke, Isle of Wight
Castle Acre, Norfolk (shell keep around an inner tower or manor House)
Clare, Suffolk (part of wall on motte only)
Fotheringhay, Northamptonshire (demolished - motte only survives)
Launceston, Cornwall
Lewes, East Sussex – two shell keeps on same site? One survives.
Lincoln, Lincolnshire – two shell keeps on same site? One survives.
Oxford, Oxfordshire
Pickering, North Yorkshire
Restormel, Cornwall (excellent example)
Tamworth, Staffordshire
Tonbridge, Kent (foundations on motte only)
Totnes, Devon
Trematon, Cornwall
Warwick, shell demolished and incorporated into bailey wall post-medieval
Wigmore, Herefordshire
Windsor, Berkshire (re-modelled post-medieval)
Wiston (Wales)
In addition Farnham and Berkeley castles have stone enclosed mottes which may be interpreted as shell keep variations. At other sites such as Durham, Warkworth, Clifford's Tower (York) and Sandal (Wakefield), shell keeps may have evolved into a tower proper. Clifford's Tower is often interpreted by modern visitors as a shell keep due to explosion damage, in 1684, which removed the roof and its central supporting masonry. True shell keeps were a stone wall around the upper perimeter of the motte with lean-to buildings against this outer wall and a small courtyard in the middle. See Restormel plan below.
Unusually Lewes and Lincoln castles both feature two separate mottes which may have had shell keeps upon both of them. The reason for this is unclear but given that Lincoln Castle is adjacent to the cathedral, one shell keep may have been for the castellan (castle holder) and the other for the bishop. In each case, only one shell keep survives.
The shell keep of Windsor Castle was built by Henry II and remodelled in the 19th century.
shellkeep is a style of medieval fortification, best described as a stone structure circling the top of a motte. In English castle morphology, shell...
and was a term applied to the shellkeep at Guînes, said to resemble a barrel. The term came to be used for other shell keeps by the 15th century. By...
"shellkeep" (a hollow enclosure) of this date. These ruins are fragmentary but indicate that there were towers to the north and south of the shell keep...
(Dutch pronunciation: [ˈbʏr(ə)xt fɑn ˈlɛidə(n)]; Fort of Leiden) is an old shellkeep in Leiden constructed in the 11th century. It is located at the spot where...
began to be rebuilt in stone, probably by Robert of Gloucester, with a shellkeep and substantial defensive walls being erected. Further work was conducted...
Shell USA, Inc. (formerly Shell Oil Company, Inc.) is the United States-based wholly owned subsidiary of Shell plc, a UK-based transnational corporation...
Bramber, who is probably responsible for constructing the first stone shellkeep and walls on the site. By 1326, the castle had fallen into ruin and was...
him permission to rebuild the castle. Fitzharding built the circular shellkeep between 1153 and 1156, probably on the site of the former motte. The building...
Restormel Castle is an unusually well-preserved example of a circular shellkeep, a rare type of fortification built during a short period in the 12th...
were driven in to support the motte and the old wooden keep was replaced with a new stone shellkeep, with a probable gateway to the north-east and a new...
The two principal elements in their construction were the great tower or keep, such as the White Tower, and the fortified enclosure, such as is provided...
ground. Before 1100, the de Clares replaced the wooden castle with a stone shellkeep. This was reinforced during the thirteenth century, and in 1295 a stone...
massive foundations of a Norman tower and then totally enclosed by a shellkeep, with buttress turrets and a shallow gatehouse. Attached to the motte...
saved his life at the Battle of Waterloo in 1815. The house resembled a shellkeep, and was built of flint and had living quarters built into the walls on...
stone shellkeep. The current inner ward was originally the bailey, and was built between 1180 and 1187. The keep was developed into a stone shellkeep sometime...
around the top of the motte creating what is known as a shellkeep, and then around the 1130s a keep (tower) was added, again made of Bargate stone from nearby...
of shellkeep at Guildford Castle (Grade I) (1177988)". National Heritage List for England. Alexander 2006, p. 19 Historic England. "The castle Keep (Grade...
Fortified Centre of Wareham and Part of the Motte and Bailey Castle with ShellKeep", Historic England, retrieved 26 August 2016 Royal Commission on the Historical...
The Z shell (Zsh) is a Unix shell that can be used as an interactive login shell and as a command interpreter for shell scripting. Zsh is an extended...
Shell shock is a term that originated during World War I to describe the type of post-traumatic stress disorder (PTSD) that many soldiers experienced...
period had a high tower, called a donjon or keep, usually surrounded by a lower wall, called a shellkeep. The earliest were rectangular, but were usually...
Margaret. Archaeological findings show that it was rebuilt in stone as a shellkeep castle in the 13th century. The purpose of the castle appears to have...
I, replaced the motte with a shellkeep. By about 1230 a tall cylindrical keep was added to the inside of the shellkeep, possibly by his great-grandson...
keep is the 13th-century high tower, 12 metres (39 ft) in diameter, constructed from dark shale. This replaced any internal rooms that the shellkeep...
timber castle on the site as part of the pacification of Somerset. A stone shellkeep was built on the motte by the start of the 12th century, and the castle...
A shell script is a computer program designed to be run by a Unix shell, a command-line interpreter. The various dialects of shell scripts are considered...
of the octagonal keep and outlying earthworks. In September 2007 Hampshire County Council undertook a restoration of the shellkeep under guidance from...
Global Information
The shell keep of Windsor Castle was built by Henry II and remodelled in the 19th century.
Restormel Castle built around the motte
Plan of Restormel Castle
Tamworth Castle, Staffordshire
Totnes Castle, Devon
Wiston Castle, Pembrokeshire
