Castles in Great Britain and Ireland
Castles have played an important military, economic and social role in Great Britain and Ireland since their introduction following the Norman invasion of England in 1066. Although a small number of castles had been built in England in the 1050s, the Normans began to build motte and bailey and ringwork castles in large numbers to control their newly occupied territories in England and the Welsh Marches. During the 12th century the Normans began to build more castles in stone – with characteristic square keep – that played both military and political roles. Royal castles were used to control key towns and the economically important forests, while baronial castles were used by the Norman lords to control their widespread estates. David I invited Anglo-Norman lords into Scotland in the early 12th century to help him colonise and control areas of his kingdom such as Galloway; the new lords brought castle technologies with them and wooden castles began to be established over the south of the kingdom. Following the Norman invasion of Ireland in the 1170s, under Henry II, castles were established there too.
Castles continued to grow in military sophistication and comfort during the 12th century, leading to a sharp increase in the complexity and length of sieges in England. While in Ireland and Wales castle architecture continued to follow that of England, after the death of Alexander III the trend in Scotland moved away from the construction of larger castles towards the use of smaller tower houses. The tower house style would also be adopted in the north of England and Ireland in later years. In North Wales Edward I built a sequence of militarily powerful castles after the destruction of the last Welsh polities in the 1270s. By the 14th century castles were combining defences with luxurious, sophisticated living arrangements and heavily landscaped gardens and parks.
Many royal and baronial castles were left to decline, so that by the 15th century only a few were maintained for defensive purposes. A small number of castles in England and Scotland were developed into Renaissance Era palaces that hosted lavish feasts and celebrations amid their elaborate architecture. Such structures were, however, beyond the means of all but royalty and the richest of the late-medieval barons. Although gunpowder weapons were used to defend castles from the late 14th century onwards it became clear during the 16th century that, provided artillery could be transported and brought to bear on a besieged castle, gunpowder weapons could also play an important attack role. The defences of coastal castles around the British Isles were improved to deal with this threat, but investment in their upkeep once again declined at the end of the 16th century. Nevertheless, in the widespread civil and religious conflicts across the British Isles during the 1640s and 1650s, castles played a key role in England. Modern defences were quickly built alongside existing medieval fortifications and, in many cases, castles successfully withstood more than one siege. In Ireland the introduction of heavy siege artillery by Oliver Cromwell in 1649 brought a rapid end to the utility of castles in the war, while in Scotland the popular tower houses proved unsuitable for defending against civil war artillery – although major castles such as Edinburgh put up strong resistance. At the end of the war many castles were slighted to prevent future use.
Military use of castles rapidly decreased over subsequent years, although some were adapted for use by garrisons in Scotland and key border locations for many years to come, including during the Second World War. Other castles were used as county jails, until parliamentary legislation in the 19th closed most of them down. For a period in the early 18th century, castles were shunned in favour of Palladian architecture, until they re-emerged as an important cultural and social feature of England, Wales and Scotland and were frequently "improved" during the 18th and 19th centuries. Such renovations raised concerns over their protection so that today castles across the British Isles are safeguarded by legislation. Primarily used as tourist attractions, castles form a key part of the national heritage industry. Historians and archaeologists continue to develop our understanding of British castles, while vigorous academic debates in recent years have questioned the interpretation of physical and documentary material surrounding their original construction and use.
Norman Invasion
Earlier castles and fortifications
The English word "castle" derives from the Latin word castellum and is used to refer to the private fortified residence of a lord or noble. The term tends not to be used for buildings earlier than the 11th century, but such defensive structures are known to have existed before the Norman conquest. A lack of archaeological evidence for timber buildings has tended to disguise the extent of castle-building throughout Europe prior to 1066, and many of the early wooden castles were built on the site of earlier fortifications.Before the arrival of the Normans the Anglo-Saxons had built burhs, fortified structures with their origins in 9th-century Wessex. Most of these, especially in urban areas, were large enough to be best described as fortified townships rather than private dwellings and are therefore not usually classed as castles. Rural burhs were smaller and usually consisted of a wooden hall with a wall enclosing various domestic buildings along with an entrance tower called a burh-geat, which was apparently used for ceremonial purposes. Although rural burhs were relatively secure their role was primarily ceremonial and they too are not normally classed as castles.
The presence of castles in Britain and Ireland dates primarily from the Norman invasion of 1066. There were, however, a small number of castles built in England during the 1050s, by Norman knights in the service of Edward the Confessor. These include Hereford, Clavering, Richard's Castle and possibly Ewyas Harold Castle and Dover.
Invasion
, Duke of Normandy, invaded England in 1066 and one of his first actions after landing was to build Pevensey Castle in September 1066, Hastings Castle to protect his supply routes, and Dover Castle. Following their victory at the battle of Hastings the Normans began three phases of castle building. The first of these was the establishment, by the new king, of a number of royal castles in key strategic locations. This royal castle programme focused on controlling the towns and cities of England and the associated lines of communication, including Cambridge, Huntingdon, Lincoln, Norwich, Nottingham, Wallingford, Warwick and York. Of the castles built by William the Conqueror two-thirds were built in towns and cities, often those with the former Anglo-Saxon mints. These urban castles could make use of the existing town's walls and fortifications, but typically required the demolition of local houses to make space for them. This could cause extensive damage, and records suggest that in Lincoln 166 houses were destroyed, with 113 in Norwich and 27 in Cambridge. Some of these castles were deliberately built on top of important local buildings, such as the burhs or halls of local nobles, and might be constructed so as to imitate aspects of the previous buildings – such as the gatehouse at Rougemont Castle in Exeter, which closely resembled the previous Anglo-Saxon burh tower – this was probably done to demonstrate to the local population that they now answered to their new Norman rulers.The second and third waves of castle building were led by the major magnates, and then by the more junior knights on their new estates. The apportionment of the conquered lands by the king influenced where these castles were built. In a few key locations the king gave his followers compact groups of estates including the six rapes of Sussex and the three earldoms of Chester, Shrewsbury and Hereford; intended to protect the line of communication with Normandy and the Welsh border respectively. In these areas a baron's castles were clustered relatively tightly together, but in most of England the nobles' estates, and therefore their castles, were more widely dispersed. As the Normans pushed on into South Wales they advanced up the valleys building castles as they went and often using the larger castles of the neighbouring earldoms as a base.
As a result, castle building by the Norman nobility across England and the Marches lacked a grand strategic plan, reflecting local circumstances such as military factors and the layout of existing estates and church lands. Castles were often situated along the old Roman roads that still formed the backbone for travel across the country, both to control the lines of communication and to ensure easy movement between different estates. Many castles were built close to inland river ports and those built on the coast were usually located at the mouths of rivers or in ports, Pevensey and Portchester being rare exceptions. Some groups of castles were located so as to be mutually reinforcing – for example the castles of Littledean Camp, Glasshouse Woods and Howle Hill Camp were intended to act as an integrated defence for the area around Gloucester and Gloucester Castle for Gloucester city itself, while Windsor was one of a ring of castles built around London, each approximately a day's march apart. Some regional patterns in castle building can also be seen – relatively few castles were built in East Anglia compared to the west of England or the Marches; this was probably due to the relatively settled and prosperous nature of the east of England and reflected a shortage of available serfs, or unfree labour.
Not all of the castles were occupied simultaneously. Some were built during the invasions and then abandoned while other new castles were constructed elsewhere, especially along the western borders. Recent estimates suggest that between 500 and 600 castles were occupied at any one time in the post-conquest period.