Menno baron van Coehoorn

March? 1641- 17 March 1704


Menno van Coehoorn descended from a family that had its roots in Germany and had come to the United Provinces with the troops of William of Orange. Menno's father had been the first to settle in the vicinity of Leeuwarden. Here Menno was born around March 1641 at Lettingastate, one of the tiny manors typical to the petty nobility of Frisia.

Early career

In 1657 Menno van Coehoorn joined the company of his father. While being a lieutenant in 1659 he became a captain on 4 October 1660. Coehoorn first saw action when he marched with the regiment of Ernst van Aylua against the army of the bishop of MŁnster who had invaded the north eastern part of the United Provinces. When the French threatened to invade the United Provinces Coehoorn, who was then in the regiment of Gerrit van Amama, was sent to Maastricht. At the famous siege that started on 6 June and ended on 2 July 1673 Coehoorn was in the excellent company of Louis XIV, Vauban, Marlborough, Villars and D'Artagnan. Coehoorn became an ADC to the Rhinecount of Salm who commanded the Dutch side. Not much is known about his role during the siege of Maastricht except that he was wounded and supposedly drew some conclusions about siege warfare. In 1674 Coehoorn was present at the battle of Seneffe where he behaved himself so well that he was formally appointed as major on 21 November 1674. In September 1674 Coehoorn was sent to Grave were he worked at the siege till the capitulation on 26 October. It is widely supposed that during the siege of Grave the Cohorn mortar was first used, but Joep van Hoof has explained this to be a misunderstanding1. Coehoorn's next major action was the battle of Montcassel on 10 April 1677. For Coehoorn this war was concluded at the battle of Saint Denis on 15 August 1678. His next promotion came when he was appointed Lieutenant Colonel of the regiment Nassau Friesland on 22 February 1679.

Menno van Coehoorn as Colonel

In 1678 Coehoorn married Magdalena van Scheltinga, who died in 1683 after giving birth to four children. Even though his appointment in February 1679 seems to point to Coehoorn having good relations to Stadhouder Hendrik Casimir of Frisia it seems that his relations at the Leeuwarden Court soon soured. After the peace of Nijmegen gave the United Provinces some breathing space a program to improve the fortifications was started. Lieutenant Colonel Coehoorn and Captain Louis Paen, who were both in the same Frisian regiment, then started a dispute about how the fortress of Coevorden should be improved. In 1681 the subject was formally discussed on paper, but in 1682 Coehoorn published 'Versterckinge des Vijfhoeks' (fortification of the pentagon) in which he gave his view on the dispute with Paen. In this conflict Coehoorn got assistance from his nephew Bernardus Fullenius Junior, a professor of mathematics at the University of Franeker who was interested in the art of fortification.

As part of a larger building program work had started on the reconquered fortress of Grave in 1680. In June 1683 Coehoorn traveled to the site in order to inspect it. It soon became apparent that the work had suffered from fraud, and therefore Coehoorn developed his own plan to refortify Grave. Even though Coehoorn's plan was not executed he would include his plan in his famous publication 'Nieuwe Vestingbouw op een natte of lage horisont' that was published in 1685. This work focused on building fortifications in low lying terrain. To appreciate its influence one only has to know that later on it was translated in French, German, English and Russian. However, in the years immediately following this publication Coehoorn did not get any assignment to work on fortifications.

Menno van Coehoorn during the war of the ligue of Augsburg

Even though Coehoorn had made a name for himself with his publication the lack of any assignment meant that he again went on campaign in his normal capacity as colonel of the Nassau Friesland Regiment. This led him to the siege of Kaiserswerth that lasted from 21 June to 26 June 1689. Next came the siege of Bonn that was surrounded on 3 July. Because of other operational concerns the siege only started on 16 September, and lasted till 10 October. It is assumed that even though Coehoorn had no formal role in this siege he had a heavy influence on the way it was conducted.

In 1690 Coehoorn marched from Brussel to Charleroi with the allied army under the Dutch Marshal Waldeck. Here it was met by the French under Marshal Luxembourg at Fleurus. In Waldeck's left wing, which was commanded by the Frisian Stadholder Hendrik Casimir II, we find Coehoorn who commanded a brigade that comprised two of his own battalions as well as six others. It was this wing that then came under an enveloping attack by Luxembourg that was not noticed in time. I do not know details about this attack but fact is that even though the wing suffered heavy losses, it succeeded in withdrawing intact from the battlefield. The army had thus suffered a tactical defeat, but for Coehoorn there were happy consequences: One of the colonels of the Frisian Regiments had been killed in the battle, and Coehoorn became its Colonel in stead of being only Lieutenant Colonel of the Nassau Friesland regiment. For Coehoorn this also meant he could get closer to William III because his new position was less dependent on the Frisian Stadholder.

In 1691 William III ordered Coehoorn and his regiment to Namur. Coehoorn also got the assignment to improve its defense, which meant he got his first assignment as engineer. Coehoorn executed this assignment by constructing Fort William and La Casotte. In May 1692 Vauban surrounded the city under the eye of Louis XIV while Luxembourg covered the siege. Vauban executed the siege methodically and first conquered the city and then la Casotte on 13 June. Coehoorn, who commanded the 1,500 strong garrison of Fort William then came under a heavy artillery barrage followed by an assault on 22 June. The next day the garrison capitulated, and on marching out of the fortress a heavily wounded Coehoorn was met by Vauban. The siege was ended by the surrender of the citadel on 1 July. Coehoorn was honored by Vauban renaming Fort William to Fort Coehoorn.

Coehoorn's conduct during the siege was rewarded on 26 July 1692 when he was appointed as Major general (Generaal Majoor) which brought about his entrance in the circle of senior officers. Later on in 1692 Coehoorn went to command at Liege. Here he got the assignment to prepare the defense of Liege and Huy (Zoutleeuw). Coehoorn did this by improving the fortress La Chartreuse and constructing some lines around the city which were completed by May 1693. At Huy Coehoorn was less successful, because it was taken by the French in July 1693. In 1694 Coehoorn reconquered Huy in September. Though Coehoorn thus did not see much action at Liege his constructions may have been successful in deterring a French attack on the city.

In 1695 William III performed some maneuvering in Flanders and then suddenly surrounded Namur at the end of June. Since its conquest Vauban had considerably improved its fortifications, and now Boufflers defended it with a garrison of 18,000 men. William III entrusted the operation to two senior officers, of whom one was put out of action by the enemy. Coehoorn came to the siege in July, and after some arguments William made him commander of the operation. Coehoorn quickly concentrated the artillery against a part of the city and after an assault the city itself was surrendered on 3 August. On 30 August Coehoorn executed an assault on Fort Coehoorn and Terra Nova, and even though it suffered 2,000 casualties it compelled Boufflers to surrender these works on 1 September. What is remarkable about the method Coehoorn used is that he assaulted these works before all trenches were complete. In this approach he differed from Vauban's method that saved lives but cost more time.

Coehoorn's conquest of Namur was a decisive event during the war of the Ligue of Augsburg. For his exertions he was rewarded well: he was appointed Lieutenant General on 30 September; on 16 October he was appointed Ingenieur Generaal der FortificatiŽn; he got a Holland Regiment to command while his old Frisian Regiment went to his brother Gideon, and finally he was made a baron by Charles II of Spain. As regards operations Coehoorn continued at Namur, which he repaired and further improved. In 1696 he executed a bombardment of Givet together with Count Athlone.

Menno van Coehoorn as head of fortifications

After peace had been signed in Rijswijk in 1697 Menno got time to execute his new job as head of the fortifications department. In 1698 he started on his first inspection trip that led him to the most important fortifications of the United Provinces. I here only mention that in Groningen his recommendations would later lead to the construction of the Helperlinie and that in Doesburg he reorganized the fortifications by designing the 'Hoge Linie', which was finished in 1701. After Coehoorn had made his report it was decided that the fortifications of Bergen op Zoom and Nijmegen would get priority. Coehoorn thus started work at Bergen op Zoom in 1698 and hired a lot of engineers to execute that work and work on a lot of other fortifications.

Menno van Coehoorn in the Spanish Succession War

On 21 June 1701 Coehoorn was appointed as Governor of Sluis and all the troops in Zeeuws Vlaanderen (the part of Flanders that was administered by the States General). As regards the war Coehoorn opposed waging a chess type war and opted for concentrating most of the troops in a field army and beating the enemy in an open battle 3). The plan of operations for 1702 differed from Coehoorn's, and so he had to execute a feint against Flanders while the campaign goal was the siege of Kaiserswerth. Coehoorn's attack resulted in the conquest of Middelburg (lost again later on), Fort Isabella and Fort Sint Donaas, while a French counter attack on Hulst failed. After Kaiserwerth had capitulated on 15 June 1702, it was decided to attack Venlo. Coehoorn was now appointed to lead the siege which lasted from 11 September till 24 September 1702. In October Coehoorn then conquered Roermond and the town of Liege, the citadel of Liege and La Chartreuse. In 1703 Coehoorn got the assignment to conquer Bonn. After he had opened the trenches in the beginning of May Bonn capitulated on 16 May. Coehoorn next played his part in Marlborough's 'grand design', which was ended with the battle of Ekeren. In February 1704 Coehoorn traveled to The Hague in order to confer about the coming campaign, but this proved to much for his weak health, and so he died on 17 March 1704. He was interred in the church of Wijckel where the Frisian States sponsored the erection of a sumptuous monument over his grave.

Generalship of Coehoorn

Not counting the Oranges the Frisian Baron Menno van Coehoorn is the most famous Dutch general of all times. As regards siege warfare he was the great rival of Vauban, and his reconquest of Namur gave him a solid reputation as a great general. On a personal level Coehoorn was honest and brave and hated flattery, but also often behaved in a way that irritated others.




The prime reference for this page is: Menno van Coehoorn 1641 - 1704, Vestingbouwer ~ belegeraar ~ infanterist by Joep van Hoof. Published by the Instituut voor Militaire Geschiedenis at the Hague in 2004. It is also mentioned at the Sources pages.


1) See Menno van Coehoorn 1641 - 1704: Page 19 which explains this legend.
2) See Menno van Coehoorn 1641 - 1704: Page 44 where Van Hoof explains how this can be deduced.
3) See Menno van Coehoorn 1641 - 1704: Page 83 this coincides with Eugen and Marlborough's view on warfare.