Abstract
Corporate expulsion—the permanent, government-sponsored banishment of a category of subjects beyond the physical boundaries of a political entity—appears to be a characteristic trait of Western European civilization. Elsewhere it occurred only sporadically. Compatible with the European states system that was taking shape during the central Middle Ages, corporate expulsion became a viable mode for coping with perceived internal threats when, from the twelfth century onward, a preoccupation with the defense of purity converged with the tendency of increasingly more efficient rulers to accentuate their responsibility for the wholesomeness of their realms. With the expansion of European civilization to other continents, this type of expulsion struck roots there as well.