Trazegnies was originally a powerful independent seigneurie on the edges of the Duchy of Brabant, the County of Hainaut and the Prince-Bishopric of Liège and was ruled by a separate dynasty.

The original castle was built by Gilles I in the 11th century but was almost completely destroyed in 1554 by the armies of Henry II of France during the Italian War of 1551–1559.

Subsequently rebuilt, a corps de logis was added to the castle by Gillion-Othon de Trazegnies in the Louis XIII style in the 17th century.

It had become derelict by 1926 and suffered severe damage from subsidence as a result of underground mining.

However, a civic association called the "Friends of Trazegnies Castle" (Les Amis du Château de Trazegnies) successfully opposed its destruction and began a gradual programme of restoration with the support of the Walloon Region.