Peter des Roches was a Frenchman. Amidst the many accounts of his career one question looms larger than any other. From his first appearance in England under King John until his death in 1238, he was to be dogged by outcry against ‘the aliens’. In 1214, it was said that his patronage and importation of aliens caused uproar and spurred on rebellion amongst the native English baronage. In 1221, he was accused of plotting together with his fellow aliens to deliver England into the hands of the French king Philip Augustus. Three years later, in 1224, he was removed from office amidst a concerted upsurge of anti-alien rhetoric. Finally, in the 1230s, his political rehabilitation was to be followed, according to the chroniclers, by the virtual subjection of England to the natives of Poitou; as one recent commentator puts it, part of a movement at the courts of King John and Henry III away from Angevin to Poitevin kingship, ‘widen[ing] the circle at court to include the king's vassals south of the Loire’. In 1234, this so-called Poitevin government was to collapse amidst native outcry against ‘the aliens’.

In all of this, one assumption has remained constant and unchallenged; that des Roches was a Poitevin, a native of Poitou, sprung from a region of France south of the river Loire; a province annexed to the Angevin dominion by Henry II's marriage to Eleanor of Aquitaine, remaining under Plantagenet control, albeit a limited degree of control, until its conquest by the Capetians in the 1220s. In terms of modern scholarship, the tradition that des Roches was a Poitevin goes back at least as far as the seventeenth century.