sentences:  Under Napoleon Bonaparte, the cathedrals were returned to the church, but were left in a lamentable state of repair.In the 13th century, the design of the "chateau fort", or castle, was modified, based on the Byzantine and Moslem castles the French knights had seen during the Crusades.The new kind of fortification was called Phillipienne, after Philippe Auguste, who had taken part in the Crusades.