Sluis Castle

Sluis Castle was a former castle located next to the town of the same name in the province of Zeeland, Netherlands.

Built around 1386 on the orders of Philip the Bold, Duke of Burgundy, it was likely modeled after the Bastille in Paris, completed just a few years earlier by French architect Drouet de Dammartin. When finished, the castle was a formidable fortress with a rectangular layout, 36 rooms, and features such as wall walks, 16 towers, and two gatehouses. Its dimensions measured 86 by 80 meters, with walls standing 15 meters high, nearly 4 meters thick, and equipped with loopholes. The towers were connected by passages built into the thickness of the walls.

The castle was situated on the right bank of an old sea arm called Zwin, which connected the sea to Bruges. As the Zwin silted up over time, Sluis became Bruges' port, with the castle providing protection for this vital harbor.

John the Fearless, who succeeded Philip as Duke of Burgundy, built a second, smaller castle on the opposite side of the Zwin at the start of the 15th century, called the "Tower of Burgundy." A chain could be hung between the two fortifications to close off the Zwin to enemy ships.

In 1537, during Charles V’s reign, the tower was demolished due to advances in cannon firepower. The castle was also modified: the eastern gate was sealed, and both gatehouses were reinforced with barbicans and earthen walls.

From 1566, Sluis Castle fell into disrepair and came under Spanish control in 1587. During the Siege of Sluis in 1604, Maurice, Prince of Orange’s troops recaptured the castle. The Spanish repeatedly attempted to retake it but failed.

In the 17th century, Dutch military engineer Menno van Coehoorn fortified both the town and castle.

In the early 18th century, some towers were dismantled to create space for gun positions. The castle played a military role in the War of the Austrian Succession from 1740 to 1748, when it was taken by the French. It was returned to the Dutch a year later. The castle was reduced to ruins by cannon fire during the 1794 French Siege of Sluis, and the French partially demolished it afterward.

After the French departure in 1815, the remaining ruins were cleared in 1820, and its stones were repurposed to strengthen the shores of the Western Scheldt River.

Today, nothing remains of Sluis Castle except a small grassy elevation called the "castle hill," which marks the site of the former courtyard.

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