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 Octavius Ignatius, Prince of Arenberg and Barbançon, totalled approximately 6,000.