General readers have in recent years been presented with a wide range of broad-brush histories of the Crusades. Many of these books, including Christopher Tyerman’s God’s War (2006), offer narrative accounts of the origins, development and diversification of the crusading movement, with differing emphases and chronologies, from those that focus on the subject’s “golden age” in the twelfth and thirteenth centuries to others that consider the legacy of crusading down to the modern period. In his new book, Tyerman offers a rather different proposition. How to Plan a Crusade is not so much concerned with events that took place during the series of military exped­itions that were dispatched to the eastern Mediterranean during the central Middle Ages. There are