The Flanders town of Courtrai (Kortrijk) lies on the river Lys some distance to the north-east of Lille. It was founded by the Romans as Cortoriacum and was first fortified in the 9th century against the threat of Norman invasion.
These fortifications were enlarged at the end of the 12th century when the town had outgrown its earlier walls. In the middle ages the town prospered due to its textile industry, but it also suffered from the conflict between France and the Counts of Flanders.
During the 80 Years War'Courtrai rebelled against Spain, but was taken by surprise by Parma in 1580. The early 17th century saw the Spanish strengthen the fortifications further by the construction of demi-lunes'in front of the medieval walls to the south and west of the town.
The threat this time was not the rebellious Dutch to the north but the French, who were invading the Spanish Netherlands from the south. The first of many attacks came in 1646.
A French force under Gaston d’Orléans laid siege to Courtrai and the town surrendered just as the besiegers were about to raise the siege, having run out of powder. The French governor, maréchal de Gassion, immediately set about strengthening the defences.
The main result of these improvements was the construction of a large pentagonal bastioned citadel'to the east of the old town. This not only strengthened the town against attack, but served as a means of subduing the population should they think of rebelling against the occupying French forces.
There were also grand plans to entirely revamp the defences on the south and west sides of the old town, where the fortifications consisted of the old medieval wall fronted by a ditch and some demi-lunes. It was this weak spot that the French had been able to exploit when they attacked.
The plan was to build a continuous earthwork bastioned trace in the Dutch style with false brays'in the flanks of the bastions. The were to be demi-lunes, a strong covered way'and three hornworks'protecting the citadel (see map above right).
In the event, it seems that these plans could not all be carried out fully. The citadel was built, but there were no hornworks and the new bastions were not built. A covered way was added and two demi-lunes were constructed, one in the north and one in the south.
The reason that the plans were not fully carried out may have been that Courtrai was returned to the Spanish by the Treaty of Westphalia'in 1648. However, the French returned in 1667 under Louis XIV. They held Courtrai again until the Treaty of Nijmegen'in 1678.
During Louis XIV's wars Courtrai was thrust back and forth between France and Spain. In 1683 Vauban'directed the third French siege of Courtrai, after which he had the citadel demolished - a wise move since the French were forced to relinquish Courtrai once more in 1684.
The town was occupied again from 1689 until the Treaty of Rijswijk'in 1697 and finally from 1702 to 1706. These successive sieges occupations had taken their toll on Courtrai, which was by now far less prosperous than it had been in medieval times.
By the Treaty of Utrecht'the town was made part of the Austrian Netherlands. The town became less important as a strategic fortress and the fortifications were demolished in the mid 18th century. Courtrai had been an important frontier fortress for over fifty years and saw no less than five occupations by the French in that time. Despite its earthwork fortifications and various weak points, it was considered by Vauban to be a valuable possession, even after the demolition of the citadel.
The demolition in the 18th century and two World Wars have swept away all traces of the earthwork fortifications and almost all of the medieval walls. Today, the only remains to be seen are the impressive Broeltorens, two towers that stand either side of the river.
The southern tower, the Speyetoren, was built in 1385 to control the river. The northern tower, the Ingelborchtoren was built in 1415 and was used as an armoury. It was one of the first fortifications at Courtrai designed to take artillery.
Since the Broeltorens are the only remnants of the defences, its not really worth visiting Courtrai for its fortifications. The towers are located about half a mile from the railway station, so it is possible to take a short walk to see them when changing trains at Courtrai. Please note: in this article I have followed the English convention of referring to Flanders towns by their French names, but in the town itself Flemish is spoken and the name Kortrijk rather than Courtrai is used.