1st September 1939 the 61st were mobilized at Plymouth. On the 2nd October they landed at Cherbourg with the 3rd Division, British Expeditionary Force. The next two months were spent training and helping prepare defences east of Lille. January 7th they moved into the Maginot Line, near Metz. From there they mounted patrols. During one patrol, on the 13th January, Captain J.A. Mackenzie won the 2nd Military Cross of World War Two (Four months later he added a bar to his Cross).
In February 1940 the 61st transferred to the 145th Brigade (4th Oxfordshire and Buckinghamshire Light Infantry and the 1st Buckinghamshire Battalion), 48th (South Midland) Division. They moved to the Gort Line on the French-Belgian border.
When the Germans invaded Belgium and Holland on 18th May 1940 the B.E.F. moved into Belgium to try and stop and the invasion. The 2nd Glosters were near Tourmignies and the 5th at Auby, near Douai. On May 14th both battalions moved into Belgium, the 2nd at Heidenbroek and the 5th at Waterbosch.
May 17th the long retreat of the B.E.F. began: "It was a nightmare campaign, and what little news there was was invariably bad. The troops marched along roads crowded with refugees, subjected to frequent low-level bombing and machine-gune attacks from the air, with scanty rations and little rest. The Army wanted nothing better than to be allowed to stand and fight, but the German Blitzkrieg was so successful that there was little opportunity for that. Many French units were demoralized by treachery, and everything was alarmingly vague and bewildering."
On three occassions the BEF tried to form a line and stand, but to no avail. For four days and nights the men of the 2nd Glosters had no sleep and little food. At Coquiane they finally stopped and prepared a defensive position along the Escaut Canal near Jollain Merlin.
19th May at Leuze German bombers attacked the road on which the 2nd Battalion was travelling. A bomb hit an ammunition truck and the following explosion caused 70 casualties in the Battalion. By the end of the raid 194 men had been killed or were missing. 20th May two orders were received. The first was that there would be no rations and the Brigade was to 'live off the land'. The second was that 'the Brigade will stand and fight."
The 2nd Battalion marched to Cassel on the 25th May. While the BEF were evacuated from Dunkirk they were to hold the line.