After the Second Crusade in 1148 the Crusader States embarked on a period of caution and consolidation and, in an increasingly hostile environment, began strengthening existing fortifications and building new castles. Following on from Fortress 21 in the series, which looked at Crusader castles in the Holy Land from 1097 to 1192, this book takes the history of these military structures through to the early 14th century. David Nicolle examines the design and development of castles, the defensive strategies and construction methods used, the influence of Arabic and Islamic traditions in military architecture, as well as siege weaponry and everyday social and religious life. All this is placed within a historical context. Plans, maps, a timeline, photograhs and reconstruction drawings (by Adam Hook) are presented throughout. A tour of five examples (Margat, Crac des Chevaliers, Atlit, Caesarea Maritima and Arsuf), is also included.