After fighting the British at Mons and Le Cateau, the First Army pursued Lanrezac's French Fifth Army during the great retreat. However, thirty miles from Paris and anticipating an encounter with the French Fifth Army (commanded by Lanrezac), the cautious Bülow halted his Second Army's advance and ordered Kluck's direct support. Kluck had recently been placed under Bülow's command when the latter was appointed to command the German right wing. Kluck protested this order to Bülow and Moltke, as he preferred to move past Lanrezac's left flank, but was overruled and ordered to support Bülow's attack on Lanrezac. By this time, the aggressive Kluck had advanced his First Army well south of von Bülow's position to 13 miles north of Paris. On August 30, Kluck decided to wheel his columns to the east of Paris, discarding entirely the Schlieffen Plan. Although frustrated by Bülow's caution, on 31 August Kluck turned his army southeast to support the Second Army. In so doing, Kluck created a 30-mile gap in the German line extending toward Bülow's stalled Second Army. Critically, the move exposed Kluck's right flank in the direction of Paris where (unknown to Kluck) General Michel-Joseph Maunoury's new Sixth Army was deployed. The French learned of Kluck's change in course on September 3 thanks to reports from Allied aircraft, and this was independently confirmed by radio intercepts. The following events were critical to the future course of the war.