The 1st Battalion was a Regular Army unit stationed in Colchester on the outbreak of war in August 1914. The battalion was assigned to the 11th Brigade, 4th Division. With the division, the battalion joined the British Expeditionary Force and was sent overseas to France in August 1914, landing at Le Havre on 23 August. The 1st Battalion saw its first combat against the German Army at Le Cateau. The battalion served on the Western Front for the rest of the war, participating in many battles in 1914 alone such as the First Battle of the Marne, the First Battle of the Aisne, and the Battle of Messines. In 1914, on Christmas Day, men of the 1st Battalion participated in the legendary Christmas Truce of 1914 where British and German soldiers fraternised in No man's land. In 1915, the battalion took part in the Second Battle of Ypres, famous for its use of poison gas. In 1916 it fought at Albert and Le Transloy, which was part of the larger Somme offensive.