One of Prawer's best known works is the Histoire du Royaume Latin de Jérusalem, which won him the Prix Gustave Schlumberger of the Académie des Inscriptions et Belles-Lettres. The two-volume work presents the crusader states as a working immigrant society, and shows the importance of immigration and labor shortages. Another book by Prawer, The Latin Kingdom of Jerusalem: European Colonialism in the Middle Ages, which was intended for a larger audience, was more controversial.