Diest fortified city

Diest Fortified City

Shortly after the independence of Belgium, Diest received commanding reinforcements. With ramparts, city gates, defence canals, a fully-fledged citadel and a frontal fortress. Much of the fortified city remains intact today. Discover this ingenious piece of military architecture with views of the city and its plentiful green oases.


In early August 1831, shortly after Belgian independence, Dutch king William I made a final attempt to recapture Belgium. This warlike deed has gone down in history as the Ten-Day Campaign. The Belgian army was divided into two parts: one around Antwerp and one between Hasselt and Liege. Between them were the Kempen with Diest directly underneath. The Netherlands decided to attack the two Belgian armies from there. The capture of Belgium was in the end thwarted by French intervention.

The conclusions drawn afterwards were clear. Between Antwerp and Liege, there appeared to be no fortified place capable of slowing down an advance from the North, let alone of stopping one. In 1935, drawing on the results from a committee of inquiry, the Belgian government decided to turn Diest into a fortified city. Demer city was the chosen position on account of its strategic location. All roads from the North to Brussels ran via Diest. The city was situated halfway between Liege and Antwerp and that way it fulfilled a function as a sentry post in the Demer Valley. On 14 May 1835, Parliament endorsed the necessary credit appropriations and authorised the government to launch the works.

Bruggenhoofd (bridgehead)

Quite soon, the threat coming from the Netherlands was over for good. In 1859 it was decided that Antwerp, Liege and Namen would be enlarged to become the backbone of the new defence system. The French-German war (1870-1871) also showed that small fortified cities such as Diest would not last long when up against the new, more powerful artillery. Diest's fate as a fortified city was definitively sealed in 1895. The core fortress and Fort Leopold were downgraded, while the citadel experienced the same fate eleven years later. Diest was left orphaned and was sometimes rather disparagingly referred to as the 'bridgehead on the Demer'. 

More info about the Citadel

More info about Fort Leopold


City fortifications and 'Schaffense Poort' (city gate)

The construction of the city ramparts was started in 1837. A double earthen rampart with canals protected the city. Today, only one third of the ramparts of the fortifications remain.

Along the North side, the double earthen ramparts with canals had two large fortified city gates: the Schaffen and the Antwerp Gate. Only the first of these remains today. Two smaller gates have also been preserved: the Petrol Gate (with former gunpowder stores) and the Sas Gate where the Demer flowed into the city. Through an ingenious flood system, the front terrain could be flooded.