Haig crossed over to Le Havre. The BEF landed in France on 14 August and advanced into Belgium, where French took up positions on the left of General Lanrezac's French Fifth Army at Charleroi. Haig was irritated by Sir John French (influenced by Henry Wilson into putting his faith in a French thrust up from the Ardennes) who was only concerned with the three German corps in front of the BEF at Mons and who ignored intelligence reports of German forces streaming westwards from Brussels, threatening an encirclement from the British left. Although II Corps fought off the German attack at Mons on 23 August (the first British encounter with the Germans) the BEF was forced to withdraw after Lanzerac ordered a retreat exposing their right flank as well.