On 4 August 1914, the 1st Battalion, East Surrey Regiment was in Dublin. Eleven days later, mobilization completed and at full war establishment, the 1st Battalion landed at Le Havre in France, and before the end of the month was in action against the Germans. The battalion was assigned to the 14th Brigade, 5th Division, part of the original British Expeditionary Force (BEF). During the Retreat from Mons and afterwards, the battalion took part in the great battles of 1914, Le Cateau, the Marne and the Aisne. In 1915, after the Battle of La Bassée, the 1st East Surreys withstood a most determined attack on Hill 60, near Ypres. In the desperate fighting which ensued, the battalion won three Victoria Crosses and seven Distinguished Conduct Medals. Among the VCs was Lieutenant George Roupell, who later became the last Colonel of the East Surrey Regiment. In late 1915 the brigade was transferred to the 32nd Division. In 1916, the 1st Battalion took part in the great battles of the River Somme, and distinguished itself notably at Morval in September. The battalion took part in many of the great battles of 1917, such as Arras, the Third Battle of Ypres. After a four-month tour on the Italian Front, the battalion was back in France in March 1918, and was engaged in the Battles of Albert and Bapaume, and the subsequent advance to victory.