Courtyard of Ibn Tulun mosque in Cairo, Egypt. It was built in AD876 during the Abbasid dynasty. Muhammad later moved to the city of Medina and built a mosque (Islamic place of worship).

The Mongols stormed Baghdad in 1258, leaving the mighty Abbasid Caliphate in ruins. A city once known for its wealth and knowledge was reduced to ashes in a brutal conquest. Voting ends in ...