In 1184 Baldwin V, Count of Hainaut, built the first castle on the current site in Écaussinnes. The lords of Écaussinnes and their heirs the de Lalaings altered the original structure several times over the centuries.
In 1450 Marie de Lalaing married Jean II de Croÿ, descendant of the Counts (later Princes) of Chimay. By a quirk of inheritance, the castle later became the property of the Lalaing family again. They sold it in 1642 to the van der Burcht family.
In the 18th century the interior was redecorated with Rococo elements in the first floor of the Gothic hall.
References:The Château de Foix dominates the town of Foix. An important tourist site, it is known as a centre of the Cathars. Built on an older 7th-century fortification, the castle is known from 987. In 1002, it was mentioned in the will of Roger I, Count of Carcassonne, who bequeathed the fortress to his youngest child, Bernard. In effect, the family ruling over the region were installed here which allowed them to control access to the upper Ariège valley and to keep surveillance from this strategic point over the lower land, protected behind impregnable walls.
In 1034, the castle became capital of the County of Foix and played a decisive role in medieval military history. During the two following centuries, the castle was home to Counts with shining personalities who became the soul of the Occitan resistance during the crusade against the Albigensians.