Le processus d’européanisation des élites aristocratiques au pays de Galles aux XIIe et XIIIe siècles constitue le point de départ de cette étude. L’objectif est de saisir les mécanismes de la réception de la culture aristocratique continentale par la noblesse autochtone ainsi que la sélection et l’adaptation de certains modèles culturels gallois par l’aristocratie anglo-normande. Ces mécanismes sont analysés à travers le prisme de l’abbaye de Margam. Elle est considérée comme un potentiel « espace de rencontre », inhérent au processus d’interculturation des élites aristocratiques du Glamorgan du milieu du XIIe siècle à la fin du XIIIe siècle. La production scripturaire de l’abbaye de Margam, fondée en 1147 par le comte de Gloucester, offre un riche corpus documentaire qui permet de dresser le portrait de l’aristocratie laïque du Glamorgan.Le portrait qui se dégage de cette étude reflète une aristocratie laïque aux multiples facettes. Malgré une hétérogénéité culturelle et sociale se dessine la naissance d’une identité catégorielle commune aux élites aristocratiques. Acquérant un rôle d’agents de transition et de transformation, les cisterciens ont répondu aux besoins spirituels des nobles gallois et anglo-normands qui recherchaient l’intercession de la Vierge afin de réussir leur salut. Anticipant toute contestation aux transferts de propriété, le monastère a sécurisé les transactions en s’adaptant aux usages propres aux grands laïcs du Glamorgan. Cette reconnaissance des pratiques de l’aristocratie locale n’a pas évité l’éclatement de conflits, parfois violents, souvent résolus devant la cour comtale du Glamorgan. Cette dernière apparaît alors comme un second « espace de rencontre » du processus d’interculturation.En tant qu’« espace de rencontre », l’abbaye de Margam a contribué au processus d’européanisation qui a touché l’aristocratie galloise du Glamorgan. Cependant, ce concept présente des limites. L’européanisation des nobles autochtones n’a pas été complète, car ils ont conservé leur héritage culturel. Il laisse également dans l’ombre le processus inverse. L’adaptation et la sélection de modèles culturels gallois par l’aristocratie anglo-normande mettent donc en lumière le processus d’interculturation des élites du Glamorgan aux XIIe et XIIIe siècles. / The process of Europeanization of aristocratic elites in Wales in the twelfth and thirteenth centuries is the starting point of this study. It aims at understanding the mechanisms underlying the reception of the Continental aristocratic culture by the local aristocracy as well as the selection and adaptation of some Welsh cultural elements by the Anglo-Norman aristocracy. In order to grasp these mechanisms, this study revolves around Margam Abbey. It is considered as a possible “meeting place”, inherent to the process of interculturation of the Anglo-Norman and Welsh aristocratic elites from the mid-twelfth century to the end of the thirteenth century. The written production of Margam Abbey, founded by the earl of Gloucester in 1147, gives a rich corpus to draw the portrait of the lay aristocracy in Glamorgan.The portrait made in this study is representative of a multifaceted lay aristocracy. In spite of a cultural and social heterogeneousness, the birth of a common class identity to the aristocratic elites draws. Obtaining a role of agents of transition and transformation, the Cistercians answered the spiritual needs of the Welsh and Anglo-Norman nobles, all seeking the Holy Virgin intercession in order to win their salvation. In order to prevent any claim to transfers of property, the monastery secured the transactions by different adaptations to the specific practices of the lay aristocracy of Glamorgan. This recognition of the aristocratic particularities did not avoid the breaking of conflicts, sometimes violent, often settled before the county court. This latter appears as a second “meeting place” of the process of interculturation.As “meeting place”, Margam Abbey contributed to the Europeanization impacted the lesser Welsh aristocracy in Glamorgan, who adapted to the Continental models. However, this concept presents some significant limits. The Europeanization of the native elites was not complete, because they kept their cultural inheritance. It does not also shed light on the reverse process. So, the adaptation and selection of Welsh cultural elements by the Anglo-Norman aristocracy highlight the process of interculturation of the aristocratic elites in Glamorgan.

In and around the 870s, Britain was transformed dramatically by the campaigns and settlements of the Great Army and its allies. Some pre-existing political communities suffered less than others, and in hindsight the process helped Scotland and England achieve their later positions. By the twelfth century, the rulers of these countries had partitioned the former kingdom of Northumbria. This thesis is about what happened in the intervening period, the fate of Northumbria's political structures, and how the settlement that defined Britain for the remainder of the Middle Ages came about. Modern reconstructions of the era have tended to be limited in scope and based on unreliable post-1100 sources. The aim is to use contemporary material to overcome such limitations, and reach positive conclusions that will make more sense of the evidence and make the region easier to understand for a wider audience, particularly in regard to its shadowy polities and ecclesiastical structures. After an overview of the most important evidence, two chapters will review Northumbria's alleged dissolution, testing existing historiographic beliefs (based largely on Anglo-Norman-era evidence) about the fate of the monarchy, political community, and episcopate. The impact and nature of ‘Southenglish' hegemony on the region's political communities will be the focus of the fourth chapter, while the fifth will look at evidence for the expansion of Scottish political power. The sixth chapter will try to draw positive conclusions about the episcopate, leaving the final chapter to look in more detail at the institutions that produced the final settlement.