From 5 April, the 'Cathars' will be at the heart of a major exhibition in Toulouse, but the inverted commas chosen by the organisers are important, as the term itself and what it covers divide historians deeply today. Hundreds of objects (archives, archaeological items, reconstructions, etc.) will be on display, retracing the crusade launched in the South of France at the beginning of the 13th century by Pope Innocent III, while taking stock of the historical debates surrounding the "Cathar heresy". IMAGES AND SOUNDBITES