With the exception of David Carpenter's chapter, all the papers in this volume were presented at the Third International Conference held under the auspices of the Centre for Late Antique and Medieval Studies at King's College London in the Great Hall of the College in April 1998. The theme was ‘Nobles and Nobility in the Middle Ages’, and the conference was planned to enable comparisons to be made across time, from the fifth to the late fifteenth century, and between very different areas and phases of political development, embracing regions as diverse as England (before and after the Norman Conquest), France, Poland, the Romano-German empire, Norway, and Portugal. One of the highlights of the conference was a performance of courtly music presented in the College Chapel by members of the College Choir, under the direction of Mr David Trendell.

Our grateful thanks are due to the British Academy, the Royal Historical Society, and the Humanties Research Committee of King's College London, all of whom provided financial assistance for various aspects of the Conference; to the Isobel Thornley Bequest, whose generous grant made possible the publication of this volume; to the Music faculty of King's for use of the Viscount St David's Room; to the Dean of King's, who allowed the College Chapel to be used for the concert; and to Janet L. Nelson, who translated the papers presented by Martin Aurell and Régine Le Jan.

In addition, the editor wishes to thank the Musées du Mans and the Radio Times Hutton Picture Library for permission to reproduce the illustrations in Plates 1 and 2.

The motto of this paper is taken from the writings of a man who was made noble, rather than born such: Alfred, Lord Tennyson. In his version of the story of King Arthur, The Idylls of the King, Tennyson describes a world of petty rulers struggling among themselves and reluctant to yield to Arthur's authority: ‘… for most of these,/ colleaguing with a host of petty kings,/ Made head against him, crying, “Who is he/ That he should rule us?” ‘This sort of question was asked with some urgency in the Carolingian world of the late ninth century as the descendants of Charlemagne lost their monopoly of the kingship to ‘petty kings’, reguli. These petty kings came from the ranks of the aristocracy. How did they make the leap from nobility to royalty? What sort of power and authority did they have to acquire before they could make this leap and how, and how well, did they convince their peers of their special status? One well-known answer to the question is Karl Ferdinand Werner's argument that the component parts of the Carolingian empire, the regna within the regnum, emerged as territorial principalities. Such a view has much to commend it, but its sheer loftiness, its view of long-term processes across the whole empire, means that it pays insufficient attention to the crisis of legitimacy that was a real concern for contemporaries as this new world emerged. At the political level, and probably at the structural level too, Jean Dunbabin's characterization of the new kingdoms and principalities as ‘a series of brilliant improvisations’ is, I think, more helpful for us in our attempt to reconstruct the realities of political upheaval.

I will explore these upheavals through considering the careers of two men, great magnates of the late ninth and tenth centuries: Boso of Vienne and Arnulf ‘the Bad’ of Bavaria. Both men established formidable power bases: Boso a kingdom based in Provence and Burgundy, and Arnulf in Bavaria, a duchy understood by contemporaries to be a regnum. Yet the achievement of both men was ephemeral. Boso was hounded by the Carolingian kings and Arnulf remained duke, not king.