Solre-sur-Sambre Castle

Solre-sur-Sambre Castle is a historic water castle located in the municipality of Erquelinnes within the province of Hainaut, Wallonia, Belgium. Situated strategically at the confluence of the Thure and Sambre rivers, this fortress was originally constructed in the late 13th or early 14th century to defend the border near an enclave of the former Principality of Liège. Recognized as one of the oldest fortified structures in the region, the castle exemplifies medieval military architecture with its distinctive quadrilateral layout and circular towers reinforcing each corner. The original design featured a massive rectangular keep with small defensive openings and retractable ladder access, which was later incorporated into a larger square complex where the keep served as a gate tower.

Throughout its long history, the castle has witnessed significant conflict and ownership changes among prominent noble families. Initially held by the Barbençon family, it passed to the de Mortagne and Carondelet families, the latter of whom added a floor and conical tower tops around 1500. The site played a notable role during the Eighty Years' War when attacked by Viscount Turenne in 1637, and again during the Franco-Dutch War in 1677 when French troops occupied it to control a vital bridge. Ownership eventually transferred through marriage to the House of Merode in the 17th century, later moving to the Wignacourt family for over a century before being repurchased by the Merode family in 1989.

Today, Solre-sur-Sambre Castle remains a private residence owned by Prince Amaury de Mérode and is not open to the public. Despite centuries of use and modification, including the addition of smaller buildings over time, the structure retains its imposing keep-porch on the south side and much of its historical character. Its preservation offers a tangible link to the turbulent military past of the Hainaut region, standing as a testament to the evolution of European defensive architecture from the Middle Ages through the early modern period.