The head of St. Catherine is preserved in a reliquary in the Basilica of San Domenico in Siena, Italy.Catherine’s engagements with religious and political activities of the time developed into her multiple writings to Pope Gregory XI, the last Avignon Pope, in which she expressed the need for unity within the Church. Seven popes tied to the French monarchy resided in Avignon, France, and Catherine pleaded with Pope Gregory XI to return to Rome.