THE TIRED CLICHE OF modernist architecture that `form follows function' has often been applied, implicitly or explicitly, to the architecture of castles. Traditional interpretations have seen medieval castle design and development as the product of a struggle between increasingly sophisticated art of the siege engineer and the responses of the military architect. For early British castle scholars such as George T. Clark and Alexander Hamilton Thompson, the medieval castle was an essentially military phenomenon, and for long, warlike interpretations cast a shadow over the world of castle study. More recently, however, archaeologists and historians have developed an understanding of castles that reflects their broad range of functions and wider place within medieval society and landscape.
As well as being defensible strongholds and elite private residences, most castles were also the hubs of estates. The castle was also a conspicuous emblem of royal authority or seigneurial status. Such qualities are reflected not only in their physical remains, but also in their portrayal within literature and art. While one of the words most commonly identified with castles is `keep', the term is virtually unknown in medieval documentation where the term donjon was generally used. This derives ultimately from the Latin dominium (`lordship'). This word reflects the qualities of these conspicuous buildings of the medieval period not simply as the ultimate place of refuge within a fortified complex, but as a proclamation of lordly ambition.
Castles are notoriously difficult to define, not least because perceptions of what they constituted altered markedly during the period of castle-building, which in England and Wales ranged broadly from the mid-eleventh to the fifteenth centuries. What is clear, however, is that the medieval landscape was dotted with castles of all shapes, sizes and status, built by a wide range of individuals from kings, bishops and major magnates, through to petty manorial lords and sometimes their tenants. Well over 1,000 sites of all dates and types are known from across England and Wales. These cluster most thickly in border regions. In counties such as Herefordshire the density of castles exceeds one site per ten square miles, reflecting a proliferation of castle-building among the ranks of tenants and subtenants in response to insecurity in the late eleventh and early twelfth centuries. Other counties, too, could have surprising numbers of private fortifications: Essex and Northamptonshire both have in excess of thirty castles. Most of these sites survive not as impressive ruins, but as the grassed-over remains of slumped earthworks formerly supporting timber structures. These earth-and-timber castles should not be taken as representing crude forms of fortification, as recent excavations, notably at the site of Hen Domen (Powys), have shown that sites with timber buildings could be equally as defensible and impressive as their counterparts built in stone.
The distribution of medieval fortifications makes clear that castle-building was carried out not as part of any grand national strategy, but as a result of a multitude of individual decisions. While the crown may, in a broad sense, have been able to encourage or discourage private castle-building in given places and regions at certain times, and to actively discourage it in other contexts, there is no evidence of a master-plan of castle-building designed for national defence.
Another misconception is that most castles were built on hilltops. While photogenic gems such as Beeston Castle (Cheshire), Corfe Castle (Dorset) and Peveril (Derbyshire) have stunning settings that grace the pages of coffee-table books, in fact these sites are rather atypical. The domestic, administrative and economic functions of castles ensured that relatively low-lying positions with better access to communications and resources were more likely to be selected, and it is notable how many such castles are overlooked by higher ground. …