Siege of Namur ( 1692 ) The Siege of Namur , 25 May – 30 June 1692 , was a major engagement of the Nine Years ' War , and was part of the French grand plan ( devised over the winter of 1691 – 92 ) to defeat the forces of the Grand Alliance and bring a swift conclusion to the war . Namur , sitting on the confluence of the Meuse and Sambre rivers , was a considerable fortress , and was a significant political and military asset . French forces , guided by Vauban , forced the town ' s surrender on 5 June , but the citadel , staunchly defended by Menno van Coehoorn , managed to hold on until 30 June before capitulating , bringing an end to the 36 - day siege . Concerned that King William III planned to recapture the stronghold , King Louis XIV subsequently ordered his commander - in - chief , the duc de Luxembourg , to join battle with the Allies in the field , resulting in the bloody Battle of Steenkerque on 3 August . Background . As in 1691 , five large armies were created for the five major fronts of the war : Flanders , the Moselle , the Rhine , Piedmont , and Roussillon . To these was added a further force in Flanders to attack what was to be France ’ s major goal for 1692 , the important Sambre – Meuse fortress of Namur . The capture of the fortress would not only give control of the vicinity to France , but it might also inspire the Dutch to make peace ; if its capture did not lead to immediate talks , however , it would nevertheless be an important pawn at any future negotiations . To deter William from marching to the town ’ s relief , Louis arranged for a simultaneous landing in England to assist King James II in his attempt to regain his throne . This force consisted of 12 , 000 Catholic Irish troops , released after the conclusion of the Irish war under the terms of the Treaty of Limerick , supported by a similar number of French troops . However , an essential preliminary to the invasion was the acquisition of naval supremacy in the English Channel . Siege . Louis , accompanied by individuals of the court , left Versailles for Flanders on 10 May . French cavalry invested the town on the night of 25 – 26 May ; the main army arrived the following day . The French forces were even larger than Louis had gathered for the Siege of Mons the previous year : the besieging army amounted some 60 , 000 men and 151 guns ; the duc de Luxembourg ’ s army of observation – designed to prevent William coming to Namur ’ s assistance – also had about 60 , 000 men . Namur ’ s garrison , under the command of the Duke of Barbançon , totalled approximately 6 , 000 . Fall of the town . The Siege of Namur in 1692 was a particularly notable operation of King Louis ’ reign . First , the action involved the two great military engineers of the day : Vauban , who oversaw the siege , and the Dutch engineer , Menno van Coehoorn , who directed the defences of the stronghold . Second , the location and topography of the position made the siege particularly challenging . The actual town of Namur sat on low , flat land on the north bank of the Sambre , dominated by heights on all sides . But by reason of the position of its citadel ( a complex of fortifications occupying the height on the south bank between the confluence of the Sambre and Meuse ) , it was one of the strongest frontiers in Flanders . Vauban had secretly reconnoitred Namur the year before and managed to draw up plans of the town ’ s defences . Guided by these drawings , the French constructed lines of circumvallation , and positioned several large , well - equipped batteries ; trenches for three lines of advance opened on the night of 29 – 30 May . William , meanwhile , moved his forces southwest closer to Namur , whilst Luxembourg moved his army of observation east from Gembloux to Longchamps , north of the town . William hoped to bring Luxembourg to battle on the Mehaigne , but the rain - swollen river had made a crossing impossible . Most of the garrison of Namur were Spanish troops , weak and in poor condition . The garrison managed a small sortie to reinforce a battery covering the main town , but it met with limited success . Offering little resistance the town capitulated on 5 June , at which time it was agreed there would be a truce until the morning of 7 June . During this respite the garrison crossed over to the citadel complex , and the French entered the town . It was also agreed that during the rest of the siege the Allies would not fire down on the town from the heights , and , for their part , the French would not attack the citadel from that direction . In his memoirs , Jean Martin de la Colonie , a participant of the siege wrote , " It was through ignorance of the true state of the fortifications that these articles were agreed to , as it is only from the town side that the fortress could be taken , the rest being almost impregnable . " Fall of the citadel . The river Sambre separates the citadel and the town ; the weakest side of the citadel lies along this river , but due to the terms of the truce signed at the surrender of the town , the French could not attack from this direction . The section of the citadel overlooking the Meuse is on a rocky height and is inaccessible and impossible to attack . The key to the citadel , therefore , was Fort William ( named after William of Orange who had built it ) , positioned to the west of the other main strongpoints . It was in this direction that the French were obliged to attack , ( " see map " ) . The first task for the attackers was to take the outlying redoubt of La Cachotte , which covered the approaches to Fort William . The trench was opened on 8 June ; a major assault – consisting of seven battalions , accompanied by the Kings ’ Musketeers – followed on 12 June . La Cachotte fell , and Vauban turned to seizing Fort William , which was personally defended by Coehoorn . The fort was well sited , just over the crest of the rise , obscuring the stronghold from the attackers until they were almost upon it , and masking its walls from artillery fire . French sappers approached from two directions , but the recent heavy rain had made the whole operation extremely difficult . In a dramatic gesture , Coehoorn ordered his own grave dug to symbolise his commitment to defend the position to the end , but although his grave was not needed , the Dutch engineer was wounded in the head by a shell that killed his valet . The final assault on Fort William came on 22 June ; despite Coehoorn ’ s resolute defence , he and the 200 men who had garrisoned the fort , capitulated . Vauban greeted his rival the next day , consoling him that at least he had had , " … the honour of being attacked by the greatest king in the world . " To which Coehoorn replied that his real consolation was in the fact that he had forced his great rival to move his siege batteries seven times during the assault . Due to the heavy rain the roads had become virtually impassable , greatly restricting the supply of ammunition to the French gun batteries . Saint - Simon writes , " It sometimes took as much as three days to move a cannon from one battery to another . The wagons were unusable , and shells , cannon - balls , etc . , had to be transported on mules and horses … Without them nothing would have been possible . " But the surrounding country , much of it woodland , provided so little forage that the French were forced to feed their animals on leaves and branches , resulting in many losses . Hampered in this way , and lacking ammunition , Vauban had sought permission from the King to renege on their earlier treaty and attack the citadel from the side of the town ; an act that , in Vauban ’ s opinion , would be less disgraceful than raising the siege . However , after Fort William fell , the other works did not hold out long . The final capitulation came on 30 June ; the remainder of the garrison left on 1 July . To Saint - Simon , who was at the siege , this came none too soon for the besiegers , " … whose strength and provisions were nearly exhausted on account of the continual rain that had turned everything to a quagmire . " Aftermath . Louis and his entourage left Namur on 2 July and reached Versailles two weeks later . The King ordered " Te Deum s " of thanksgiving for the victory , but in the words of historian John Wolf , he may have neglected the work of his engineers when he wrote , " the " gloire " of so great a victory belong to God alone … " But although Louis had secured a great victory at Namur , the proposed descent on England was a failure . Defeat at the Battle of La Hogue in early June had denied the French naval superiority in the English Channel , thus ending any hopes of a landing . The Irish troops destined for England marched off to the Rhineland ; the French troops joined the army in Flanders or were deployed to coastal defence . Luxembourg waited while Namur was put into a state of defence before decamping on 8 July , following William III towards Nivelles . News arrived at Versailles that William was planning the recapture of Namur as soon as the Allied commander could assemble his army . Louis wrote to Luxembourg , urging him to " … march with speed … and fight him before he can establish his trenches [ before Namur ] … " On 1 August William moved to Halle . William , like Louis , also sought battle , and on 3 August he surprised and attacked Luxembourg near the village of Steenkerque . The issue was not completely decisive – both sides could claim a victory of sorts – but William left the field in French hands , thus ending the Allied threat to Namur . Little of note happened in the remainder of the campaign before they went into winter quarters . References . Secondary . city