The original Château de Coustaussa was built by the Trencavels, Viscounts of the Razès, in the 12th century. It was the stronghold of Cathars until Simon de Montfort and his Crusaders conquered it during the Albigensian Crusade. After the Crusades, the Castle came into the possession of the de Montesquieu family. The present Château was apparently still in good shape until the 19th century, when an enterprising local realised that he could turn a few Francs by stripping out and selling the woodwork.References:
Sirmione castle was built near the end of the 12th century as part of a defensive network surrounding Verona. The castle was maintained and extended first as part of the Veronese protection against their rivals in Milan and later under the control of the Venetian inland empire. The massive fortress is totally surrounded by water and has an inner porch which houses a Roman and Medieval lapidary. From the drawbridge, a staircase leads to the walkways above the walls, providing a marvellous view of the harbour that once sheltered the Scaliger fleet. The doors were fitted with a variety of locking systems, including a drawbridge for horses, carriages and pedestrians, a metal grate and, more recently, double hinged doors. Venice conquered Sirmione in 1405, immediately adopting provisions to render the fortress even more secure, fortifying its outer walls and widening the harbour.
Thanks to its strategical geographical location as a border outpost, Sirmione became a crucial defence and control garrison for the ruling nobles, retaining this function until the 16th century, when its role was taken up by Peschiera del Garda.