The Birth of Nobility analyses the enormous international field of publications on the subject of medieval aristocracy, breaking it down into four key debates: noble conduct, noble lineage, noble class and noble power. Each issue is subjected to a thorough review by comparing current scholarship with what a vast range of historical source material actually says. It identifies the points of divergence in the national traditions of each of these debates and highlights where they have been mutually incomprehensible. For students studying medieval Europe.