The 10th Battalion was formed in Dublin on 11 Feb 1916. Its roots appear to go back a few months prior to that. A report in the Kildare Observer on 12 Dec 1915, headlined "The Commercial Pals, a New Battalion " stated:-
A meeting of the committee of the above was held at 85-86 Grafton Street on Friday of last week, Sir. Wm. Fry, J.P., D.L., presiding. There was also present - Messrs. Wm. Crowe, Wm. Sibley, James Clements, John Moran, Edward H. Andrews, J.P.; Major Arthur Whewell, Alderman James Moran, J.P., hon. secretary. Brigadier-General Hammond and Capt. Law were present during the proceedings. The financial statement was submitted, which showed subscriptions to date £503 13s., and the committee approved of placing the sum of £300 on deposit receipt in the Bank of Ireland. General Hammond reported that the "Commercial" Company would be complete and ready for moving to the Curragh Camp in a week's time, and he informed the committee that owing to the great success of the "Commercial" Company movement, due to the interest taken in the matter by the committee, the authorities had decided to form a new "Tenth" Battalion of the Royal Dublin Fusiliers, and he suggested that the committee might ascertain whether the members of the "Commercial" Company, who had already joined, would prefer to remain with the Fifth Battalion or form the nucleus of the proposed new Tenth Battalion of the Royal Dublin Fusiliers, and he was prepared to give effect to the wishes of his men. It was arranged that Sir John Irwin and Alderman Moran should take the necessary steps to ascertain the views of the members of the company, and accordingly a ballot was taken on the morning of the 27th inst., with the result that an overwhelming majority were in favour of joining the new Tenth Battalion, which all concerned are satisfied will be raised very quickly and the "Commercial" Company will therefore, remain for the present at the Royal Barracks, Dublin, and the committee of the club will devote their energies in furtherance of the larger scheme.
It appears therefore that the 10th Battalion started with the formation of a "Commercial Company" with the 5th Battalion, who were based at the Royal Barracks in Dublin. Those already in this Commercial Comapny decided to become the nucleus of the new 10th Battalion.
By the time the Easter Rising occured in April 1916, there were
10th Battalion Royal Dublin Fusiliers History by month