Much more than merely being a medieval phenomenon, the appear-aiiee and proliferation of castles throughout Britain represented the enforced institutionalization of feudalism, which William the Conqueror imported from his homeland in Normandy. Feudalism originated in coirti-neirtal Europe during the latter stages of Carolingian rule, when the death of Charlemagne (Charles, King of the Franks and Holy Roman Emperor) in 814 resulted in political disunih'. Civil war and wide, spread chaos highlighted by the invasion of the Vikings and other foreign raiders, led to the development of feudal isin as a way to reestablish centralized governmental control, provide security-, and stabilize tbe economy. Essentially consisting of a network of mutual obligations, feudalism was based on personal honor and professed loyalty, each participant exchanging specific services that os-tensiblv. solidified their position within the feudal hierarchy.
Though evidently known to some degree in Anglo-Saxon Faigland, feudalism was not systemically instituted in England and Wales until the decades immediately following the Norman Conquest, and castles played a key role in its implementation. The new sociopolitical order was predicated on the establishment of lordships. The monarch (initially by King William 1 bnt by later kings as well) granted parcels of land (hefs) to individual lords (vassals, vassals-in-chief, or tenants-in-chief, later known as barons)as rewards for military service and loyalty dnring the Conquest. The lords, in turn, either subdivided tbc fiefs and appointed lesser lords (also known as vassals) to manage them or kept the largest parcels for themselves, in order to govern the land and directly reap economic and other material benefits. In return for these grants of land, the vassals paid homage to the king, paid rent (taxes), and fulfilled military obligations, as and wheir required. Depending on their social statns, vassals agreed to provide a specific number of men for an army or to serve in the castle gnard; the number of men was calculated according to the extent of the lord’s holdings.
According to R. Allen Brown, castles were the physical embodiment of the lordship: they “dominated the countryside in every way, militarily, socially, politically, administratively and economically, and all these potencies were integrated and combined in it, and given deliberate architectural expression by it.”” Their commanding presence in the landscape and their nnfamiliar, intimidating appearance provided the vehicle by which the Normans and later lords conld clearly demonstrate their supremacy within their new territory and their complete control over the conquered populace. In short, castles functioned as centers of feudal power. Their owners intentionally planted them in the countryside, not solely as defensive structures which protected the lord and his household from rampaging subjects but, more so, as offensive strongpoints from which the lord and his garrison controlled a region. Indeed, anaong their other roles, castles were an in-your-face, ever-present enforcer of subjugation and an obvious reminder of feudal obligation.
Over time, control of a lordship or fief—and the associated castle — became hereditary; heirs not only acquired vast estates but also the laborers (serfs) bound to the land. TTiree of the most powerful Norman feudal lords —Hugh d’Avranches, Earl of Chester; Roger de Montgomery, Earl of Shrewsbury; aud William FitzOsbern, Earl of Hereford —controlled the Welsh Marches, the border region between England and Wales, as unofficial kings in their own right. William the Conqueror not only granted them huge parcels of land to govern bnt also gave them the legal authority to enforce laws as if they ruled their own kingdoms. Such men used castles to demonstrate their newly acquired status w'ithin the feudal hierarchy.
In Scotland, the introduction of feudalism had less to do with conquest per se, but rather with the reigning monarch’s interest in establishing a governing system that he would head. In the early twelfth eentury, having been educated in the courts of the Henr-1, the Norman king of England, David I actually welcomed the Normans into his Scottish kingdom, encouraging their settlement with the establishment of lordships and the coneomitant construetion of castles. Among the Normans who migrated to Scotland and made names for themselves were the de Brus (or Bruce) family, the Comvns, Haigs, Hays, Ramsays, and Sinclairs, each of whom played significant roles in Scottish liistory and also erected several noteworthy strongholds, such as Blair in Perth and Kinross, Inv erlochv in Highland, Neidpath in the Borders, and Dalhousie in Mid Lothian. Interestingly, unlike the situation in the rest of Britain, many of Scotland’s pre-Norman population, including the Earls of Atholl, Fife, and Strathearn, also acquired feudal lordships.
Not only did King David I and his grandsons Malcolm IV and William I (the Lion) invite notable Norman lords and their families to move to Scotland, they also encouraged several monastic communities from France to found abbeys and priories and to spread Roman Catholicism. The mo’e-ment of Augustinian, Cistercian, and other religious orders into the Scottish Borders resulted in the construction of several major nronasteries, including those at Kelso, Melrose, Jedburgh, and Drvburgh. In England and Wales, William I of Normandy and his heirs also welcomed the development of nronastic communities, including secral in North Yorkshire, such as Rievaulx and P'ountains abbevs.
'I'he rapid spread of motte, ringwork, and stone castles throughout the British Isles was the physical manifestation of the dramatically changing social order of the times, as the Normans progressively established power bases throughout England and Wales in the decades after 1066, and shorth' thereafter moved into Scotland and Ireland.