In the late twelfth century the Lord of Saissac, Bertrand de Saissac, was a known Cathar sympathizer. He was the tutor (ie guardian) of the infant Viscount of Carcassonne, Raymond-Roger Trencavel. Raymond-Roger was also Viscount of Béziers, Albi and the Razes.
When the Abbot of Alet died in 1197 Raymond-Roger was only nine years old. It therefore fell to his guardian, Bertrand, to appoint a new Abbot according to custom. The monks meanwhile appointed their own candidate Bernard de St-Ferréol as the new Abbott. Bertrand de Saissac was not pleased by the monks’ choice. He expelled Bernard and installed his own candidate as Abbot.
At the time of the Cathar Wars (or Albigensian Crusade), Bernard was still Lord of Saissac. The Saissacs, like the Trencavels, were stripped of their lands and titles. Bouchard de Marly, one of Simon de Montfort’s lieutenants, ordered the seizing of the castle and its goods. Later, after 1234, the castle passed to Lambert de Thury, another lieutenant of de Montfort. The siegneurie was split into many parts, some of which were restored by Louis IX to the dispossessed faidit lords of Saissac.