On 9th September, 1915 the Contingent left Ireland with the Battalion for further training at Aldershot, where it was inspected by HM Queen Mary.

The Company arrived in France on 20th December, 1915. From the 27th December, 1915 to 26th August, 1916 they remained on the Loos Hulluch front. Albert was reached on the 1st September, 1916, and during the attack on Guillemont the casualties were heavy, reducing the contingent to a mere handful. The attack on Ginchy was made on the 9th September, 1916 and resulted in its capture with a large number of prisoners. From the Somme the men rested at Corbie for ten days and the boys from Hospital were glad to rejoin their friends. The next move on the 26th September, 1916 took the Company to Belgium and they there remained until after the Messines Battle which began on the 7th June, 1917 by the blowing up of 19 mines some of which had taken 2½ years to complete. On the morning of the 31st July, 1917 the Company took part in the Third Battle of Ypres and after four days were relieved, as the Battalion, had suffered heavily. They went back to the front on the 6th August, but were relieved on the 10th; to return once more on the 14th. There then occurred three attacks in 17 days, which can never be forgotten by those who survived. Ypres claimed more of our heroes than any other portion of the line.

During October 1917 it was decided to disband the 7th Battalion and amalgamate it with the 2nd Battalion of the Royal Irish Rifles, and it was during the time spent with this Battalion, that the Contingent took part in the Cambrai Battle. In December 1917 orders were received for the remainder of the Contingent to join the 2nd Battalion of the Hampshire Regiment, as many Jerseymen were already serving with that Battalion. From that time until the Armistice the men fought with that Battalion.