This is the first modern account to describe the emergence of the northern French county of the Perche, and the rise of a relatively minor noble family from obscure origins to princely power. The Rotrou family ruled the Perche from around the year 1000 until 1226. They took part in many of the most famous military engagements of the middle ages, from the Norman Conquest of England in 1066 to the recovery of territory from the Muslims in twelfth-century Spain. Their involvement in crusading initiatives was told in the popular poetry of the day, and they came to number the kings of France, England, Aragon and Sicily, as well as the Holy Roman Emperor, among their kinsmen. This narrative explains the family's transformation and consolidation of its position in the context of a vibrant and expanding society in the years after 1000, looking at their territorial ambitions, construction of a feudal clientele and operation of lordship through female family. Dr KATHLEEN THOMPSON is Honorary Research Fellow, University of Sheffield.