Riley-Smith's acclaimed book is now regarded as a classic short study. The updated fourth edition of this essential introduction features a new Preface which surveys and reviews developments in crusading scholarship, a new map, material on a child crusader, and a short discussion of the current effects of aggressive Pan-Islamism.

JONATHAN RILEY-SMITH is Dixie Professor Emeritus of Ecclesiastical History at the University of Cambridge, UK, and a Fellow of Emmanuel College, Cambridge, UK.