On 8 August General Instruction No. 1 had ordered the Fifth Army to take a position on the left of the Fourth Army, ready to attack the southern flank of German force advancing from Mézières and Mouzon, through the difficult terrain in between. All four corps covered this front until 12 August, when Joffre allowed General Charles Lanrezac to move I Corps north to Givet to oppose a potential German attempt to cross the Meuse between Givet and Namur further north, which extended the army front to . As Lanrezac became aware of the size of the German force in Belgium and wanted to reinforce the left flank by moving to Namur, Joffre refused to allow the army front to be extended to and ordered Lanrezac to keep the army in a central position near Mézières, ready to oppose a German offensive from Mouzon to Namur. On 14 August Joffre and Lanrezac met but Joffre considered that only a few German cavalry and infantry parties had crossed the Meuse. With the BEF moving to Maubeuge and Hirson a redeployment of the Fifth Army would disrupt the deployment of the other armies. On 14 August a new intelligence report showed eight German corps between Luxembourg and Liège and by the next day Joffre allowed the move of the Fifth Army north, to operate beyond the Meuse. The XI Corps was transferred to the Fourth Army and the XVIII Corps was moved from the Third Army to the Fifth Army, which was made responsible for the defence of Maubeuge.