 Complete the following phrase:  The BEF next moved to the Ypres sector, 4th Division detraining at St Omer and taking part in the Battle of Armentieres. Influenced by his sluggish corps commander, Pulteney, Wilson did not push on, and even withdrew a battalion that was making good progress, but he did eventually secure the crossings of the River Lys and the town of Armentieres. Wilsons promotion to major-general was notified on 26 October, and he was confirmed in command of 4th Division. During the 1st Battle of Messines on 1 November, 4th Divisions rifle fire held off an attack by the German Guard Cavalry Division ordered personally by the Kaiser, and did not need to retire to positions that had been prepared in the rear. The division continued to hold its line in front of Ploegsteert Plug Street Wood for the duration of the 