Oliver was born in Trim, County Meath on 6 September 1896. He was the son of Head Constable Michael Holmes and Marianne Holmes (Nee Young). He was one of two sons and five daughters. The 1901 census records Oliver with his family in Newmarket, County Cork, with the 1911 census recording Oliver at 9 Newton Street, Strabane, County Tyrone.
Oliver enlisted in the Leinster Regiment in Dublin on 11 March 1915, he was posted to the 7th (service) Battalion at Kilworth Camp, County Cork on 13 March. Upon enlisting he was recorded as being 5 foot 9 inches tall. His former profession was given as a ‘student’. The 7th Battalion, Leinster Regiment was part of Kitcheners New Armies. Service battalions were added onto existing regiments rather than creating entirely new regiments.
After training in Kilworth Camp the battalion moved to England in September 1915. They later arrived in Le Havre, France on 18 December 1915. The battalion’s most notable action was during the Battle of the Somme where they took part in the renewed offensive in September and took part in the Battle of Guillemont, 3-6 September and the Battle of Ginchy on 9 September.
On 20 November 1916 Private Holmes was commissioned a Second Lieutenant in the 7th (service) Battalion, Royal Inniskilling Fusiliers. He joined his new battalion at Locre, Belgium. The battalion spent its time at Locre either on the front line in divisional reserve. Christmas day 1916 was spent in on the front line, the day being noted as ‘quiet’.
For New Years the battalion enjoyed a dinner at Kemmel Chateau. The first few weeks of the New Year were spent at Kemmel Shelters, where it was very cold in the huts. The battalion took part in trench raids and saw some heavy shelled while on the front lines.
On 7 June 1917 the battalion took part in the Battle of Messines, where the world saw the largest man made explosion with the detonation of 19 mines, consisting of around 600 tonnes of explosives which had been placed under the German lines. The explosion would only be later surprised in size by the advent of the atomic bomb. During the battle the 7th Inniskillings came up against some minor resistance. 'D' company encountered some rifle and machine gun fire from 'Unnamed Wood'. In fact most of the casualties sustained during the battle where due to the 'friendly fire' from creeping barrage.
Later in the August, the battalion took part in Battle of Langemarck, which was part of Third Ypres. With the battle set to take place on the 16 August, the battalion made its preparations and got into place several days before. The battle began at 4:45am with the commencing of a barrage on the enemy line. The Germans opening up a barrage within minutes. The companies advanced across no-man’s land. The battle cost the battalion dearly, resulting in 16 officers wounded, missing or killed and 368 other ranks wounded, missed or killed. The battalion would not recover from this and was merged with its sister battalion, the 8th Inniskillings on 23 August 1917.
Initial reports indicated that Second Lieutenant Holmes was missing, but this soon changed to missed, believed killed. Correspondence between the War Department and Michael Holmes ensued regarding the faith of his son. It was ultimately official decided upon that he Second Lieutenant Holmes was killed on or since 16 August. His body was never found and his name is commemorated on the Tyne Cot Memorial to the Missing along with names of over 33000 other soldiers whose remains were never found/identified. At home in Ireland Oliver’s name was included on the war memorial erected in St Columba's Church, Kells.
