area between Cambrai, Valenciennes, Maubeuge and Le Cateau, the German forces on the upper Somme, Oise and the Aisne would lose the use of the two main railways to Liege, although this would not be decisive, since the line from Laon to Vervins, Hirson, Charleroi, Namur and Liege and that from Laon to Mézières and Montmédy to either Luxemburg and Treves or Thionville and Metz, would still be available to the Germans. French moves to the north were also influenced by events in the siege of Antwerp, where Termonde fell on 26 September and increased the danger that the city and the Belgian army would be lost. The new Tenth Army was ordered to concentrate around Arras and Lens. First Battle of Picardy On 18 September, the Sixth Army advance was stopped on a south-east to north-west line at Carlepont on the south bank of the Oise and Noyon on the north bank, which ended the first French outflanking move. Joffre dissolved the Second Army in Lorraine and sent Castelnau and the Second Army headquarters to the north of the Sixth Army, to take over the IV and XIII corps, along with the 1st, 5th, 8th and 10th Cavalry divisions of the French II Cavalry Corps (General Louis Conneau) from the Sixth Army. The XIV Corps was transferred from the First Army and XX Corps from the original Second Army, to assemble south of Amiens, behind a screen of the 81st, 82nd, 84th and 88th Territorial divisions protecting French communications. The Second Army prepared to advance on 22 September, on a line from Lassigny northwards to Roye and Chaulnes, around the German flank. Next day, the German II Corps joined the right flank of the 1st Army, for an attack to the south-west with the IV Corps, IX Reserve Corps and the 4th and 7th cavalry divisions. Bülow, ordered Kluck to cancel the offensive and withdraw the two corps behind the right flank of the 1st Army. On 16 September, the 2nd and 9th Cavalry divisions were dispatched from the Aisne front as reinforcements but before the retirement began, the French XIII and IV corps on the left flank of Sixth Army, with the 61st and 62nd divisions of the 6th Group of Reserve Divisions, began to advance along the Oise and met the right flank of the 1st Army between Carlepont and Noyon on 17 September. On the right