The Briennes were a highly important aristocratic family who hailed from the Champagne region of north-eastern France, but whose reach and impact extended across Europe and into the Crusader States in the Middle East. It is a highly dramatic and wide-ranging story of medieval mobility, not only up and down the social ladder, but in geographical terms as well. Although the Briennes were one of the great dynasties of the central Middle Ages, this book represents the first comprehensive history of the family. Taking the form of parallel biographies and arranged broadly chronologically, it explores not only their rise, glory and fall, but also how they helped to shape the very nature of the emerging European state system. This book will appeal to students and scholars of medieval France, the Mediterranean world, the Crusades and the central Middle Ages.