The Avignon papacy (1309-1377) represented the zenith of papal power in Europe. The Roman curia's move to southern France enlarged its bureaucracy, centralized its authority, and initiated closer contact with secular institutions. The pope's presence also attracted leading minds to Avignon, transforming a modest city into a cosmopolitan center of learning. But a crisis of legitimacy was brewing among leading thinkers of the day. The Avignon...