Palais de Papes in Avignon. One of the most famous palaces in the Christian world. For a brief period in the early 1300s, the popes moved from Rome to Avignon to escape political infighting in Rome. In 1376, Gregory XI moved back to Rome and Avignon elected it's own rival pope. The Catholic church was split apart, and the "anti-popes" ruled in Avignon until 1417, when the Catholic church merged back together under Martin V.