Şener Aktürk discusses his recent article, “Not So Innocent: Clerics, Monarchs, and the Ethnoreligious Cleansing of Western Europe.” Ethnic cleansing is often seen as a specifically modern phenomenon. But as Akturk explains, the medieval Catholic Church facilitated the ethnoreligious cleansing of Muslim and Jewish communities across Western Europe. Akturk describes the geopolitical conditions that made this possible and his findings’ implications for twentieth- and twenty-first-century ethnic cleansing in places like Cambodia, Iraq, the Soviet Union, and Syria.