Known as 87 Battery Royal Field Artillery, and based in Ireland, when the First World War broke out the battery were immediately mobilised along with the rest of 12th (Howitzer) Brigade Royal Field Artillery, under the 6th Division. It spent the war fighting in the relatively small battlefields of France and Belgium, in extremely poor conditions in the trenches of the First Battle of the Aisne, Somme, Ypres, Cambrai and the Hindenburg Line. During the Battle of Aisne, the battery fired throughout the day and night for 48 hours in the Aisne heights. A month later, the Battle of Armentières began. In August 1915, the battery saw action at the Battle of Hooge. The battery then moved to fight in the Somme. In May 1916, 87 Battery was transferred from the 12th (Howitzer) Brigade Royal Field Artillery to the 2nd Brigade Royal Field Artillery. The Battery split again, one section was peeled off to form D Howitzer Battery after joining with another section from 43 Howitzer Battery. The Battery then fought in the Battle of the Somme on 15 September 1916 to the end on 22 April 1917.