The Second World War was declared on Sunday, 3 September 1939 and the two Territorial Army battalions, the 4th and the 6th (a duplicate of the 4th), were called-up immediately. The 2nd Battalion embarked for France with the 9th Infantry Brigade attached to the 3rd Infantry Division commanded by Major-General Bernard Montgomery in October 1939. They were followed by the 6th Battalion, part of 138th Brigade with the 46th Infantry Division, in April 1940; both served with the British Expeditionary Force (BEF) and managed to return from Dunkirk after the battles of France and Belgium. After returning to England, both battalions spent years in the United Kingdom on home defence anticipating a possible German invasion of the United Kingdom. The 2nd Battalion, remaining with the same brigade and division throughout the war, then spent the next four years training in various parts of the United Kingdom before taking part in the D-Day landings in June 1944. The battalion, commanded by Lieutenant Colonel Christopher Welby-Everard was then engaged throughout the Normandy Campaign, taking part in Operation Charnwood, Operation Goodwood, and throughout the rest of the Northwest Europe Campaign until Victory in Europe Day in May 1945.