This new edition of _Byzantium and the Crusades_ provides a fully-revised and updated version of Jonathan Harris's landmark text in the field of Byzantine and crusader history. The book offers a chronological exploration of Byzantium and the outlook of its rulers during the time of the Crusades. It argues that one of the main keys to Byzantine interaction with Western Europe, the Crusades and the crusader states can be found in the nature of the Byzantine Empire and the ideology which underpinned it, rather than in any generalised hostility between the peoples. Taking recent scholarship into account, this new edition includes an updated notes section and bibliography, as well as significant additions to the text: - New material on the role of religious differences after 1100 - A detailed discussion of economic, social and religious changes that took place in 12th-century Byzantine relations with the west - In-depth coverage of Byzantium and the Crusades during the 13th century - New maps, illustrations, genealogical tables and a timeline of key dates _Byzantium and the Crusades_ is an important contribution to the historiography by a major scholar in the field that should be read by anyone interested in Byzantine and crusader history.