Researching the history of castles

Windsor Castle by Moonlight by Henry Pether 1850Uneasy times make for defence-building. It has a long history in Britain. People protected themselves and their possessions in prehistoric times with fences, banks and ditches. We can still see the impressive remains of Iron Age hillforts and brochs. The Romans built forts and walled towns. So did the Saxons. In Ireland round towers associated with monasteries and churches could be used as both belfries and strongholds.

But what we recognise as a castle - the massively fortified residence of a king or lord - really began with the Norman conquest. Such a dramatic power shift had to be reinforced. England was dotted with motte-and-bailey castles frowning down on the local populace. At first they were thrown up rapidly in timber, to be later replaced in stone. Houses might be cleared from the highest corner of a town to build a formidable stone keep. Norman castles were often built by barons as the caput (head) of the barony. I.J. Sanders, English Baronies: a study of their origin and descent 1086-1327 (1960), traces each barony.

David I of Scotland (whose sister was married to Henry I of England) encouraged Anglo-Norman barons to settle north of the border, where they built castles like those in England. Anglo-Norman lords also invaded Ireland, building castles in the areas they settled. Meanwhile the Marcher lords held great swathes of territory on the borders with Wales. Fighting against the Welsh, they penetrated deep within Wales, building castles as they went. The Welsh princes countered with castles of their own. But it was Edward I's determination to conquer Wales that produced the most spectacular of all British castles. His master builder was James St George, a Frenchman from Savoy, who designed the type of concentric castle that Edward I had seen on crusade in the Middle East, with rings of walls and round towers around a bailey.

In Scotland the violence and insecurity of the later Middle Ages, especially along the border with England, meant that tower houses were built in large numbers, eventually developing the style known as Scottish Baronial.

Defences of any kind could serve secondary purposes. For example a huge linear earthwork created to defend a kingdom might well become a political boundary. A castle could be a home. It could be the administrative centre of a widely scattered estate. It could be the headquarters of the county sheriff. Facilities could include a prison, courtroom and chapel. Naturally a castle or hillfort was a structure of high prestige. In their eagerness to point out alternative functions, some writers have altogether dismissed defence as the primary purpose for building fortifications. They have pointed out that bank-and-ditch earthworks many miles long could not have been permanently manned, or that certain castles were never besieged, or that a moat and drawbridge would not stop a determined army equipped with siege engines. This ignores the preventative power of defences. They aim to make attack difficult. Strongholds were seldom completely impregnable. However the non-military aspects of castles did predominate in times of peace. Castles built in modern times, for example the exuberant Victorian revival of Scottish Baronial, certainly have no military purpose.


Gazetteers and bibliographiesYpres Tower, Rye, Sussex, c.1633 by Sir Anthony Van Dyck (Museum Boymans-van Beuhingen, Rotterdam)


The Castle Studies Group includes members both professional and amateur from a wide range of historical and archaeological backgrounds, both in the British Isles and overseas.

Primary sources


Dixon, water-colour of Cardiff Castle, Glamorgan, Wales 1797 (National Library of Wales)Castles were popular subjects for 18th and 19th-century artists and books of engravings, listed by Anderson. For topographical views online see the lists and links by area and period in the image finder and the combined online databases under museums and art galleries.

Domesday Book

The Domesday book mentions 48 castles. References to thenumber of houses destroyed to clear space for a castle gives an idea of the degree ofdisruption caused by Norman castle-building.

Building accounts

Surviving accounts are mainly for castles belonging to the English (later British) monarchy, which are preserved in the National Archives. References to them are included in Colvin, H.M. et al, The History of the King's Works. 6 vols. (RCHME 1973-82). A few are in print:

Chronicles and travel descriptions

See primary sources in print.

Licences to crenellate

Pontefract Castle, Yorkshire, c.1633 by Joos de Mompers (Collection Her Majesty the Queen) In medieval England, Ireland and Wales a royal licence to crenellate was required for private fortifications. Most of these are recorded in The Calendar of Patent Rolls (Henry III to Elizabeth). A list from the Patent Rolls was drawn up by J.H.Parker, Some Account of Domestic Architecture in England from Richard II to Henry VIII (1859), Vol. 3, pp.401-22; also printed in the Gentleman's Magazine 1856.

Charles Coulson has prepared an enlarged list, from which Thompson listed licences to bishops, and Emery those for England and Wales. An updated version for England and Wales is online at The Gatehouse: licenses to crenellate.

For post-medieval fortifications see public buildings. For town walls and gates see Town Walls.