Brian A. Catlos, is giving the keynote at the The Early Hafsid Caliphate, a Symposium Organized by the American Institute for Maghrib Studies (AIMS) and the Centre d’Etudes Maghrébines àTunis (CEMAT) titled “The Principal of Convenience, Physics of Scale, and Christian-Muslim Relations in the Hafsid Caliphate and Beyond” in Tunis Tunisia.