When war ended, the hard work began. Crusader warfare was only the beginning, for after peace came huge and often fundamental changes for individuals and societies. First it was necessary to establish firm and secure agreements between enemies, and take care of prisoners of war and refugees. Soon followed new legal systems, and new social groups emerged as old and new families intermarried, or entire segments of the population became subordinates under new rulers. And in a longer time perspective, the entire physical landscape was changed to conform to and express the beliefs and values of the conquerors. The military expeditions of the medieval crusades are well studied, at different times and in many diverse areas, but the consequences for individuals and societies much less. This book opens up a new research area, and contributes with 11 studies covering the Middle Eastern crusader states, the Mediterranean, and the Baltic Sea.