The fortress city of Carcassonne is a 13th century world of towers, turrets, and cobblestone alleys. This became a center of the Cathars — a heretical group of Christians who thrived around here from the 11th through the 13th centuries. As France was working to consolidate its central power, it clamped down on feisty regions like this… especially if they were sympathetic to heretical groups like the Cathars. When driven out of Carcassonne, many Cathars hid in the nearby castles of Lastours. Back in Paris, the king wanted to tighten his grip on southern France.