Meanwhile on the 1st January, 1915, by which date old Artists and others were beginning to arrive from the Colonies for training as Officers, a third Battalion, “3/28th London” had been started (at first severely restricted to two Companies under a Major), in which all subsequent recruits had to be enrolled. It was placed under the command of Lt.-Col. William Shirley, an old friend of the Corps, recently retired from the Indian Army, who had been acting as Second-in-command of 2/28th. He brought very special qualifications to the post, having been for some years an Army Instructor in India, at Sandhurst, and at Cambridge University, where on the outbreak of war he was holding the appointment of Director of Military Studies. On occasions this Battalion, which was principally officered in the first instance by senior N.C.O’s sent home for the purpose from 1/28th in France, was over 3,000 strong and in 3½ years had passed 9,352 recruits through its ranks. After a period of recruit training in London, which included the construction at Kenwood of a series of entrenchments and dug-outs on the most up-to-date Continental models, it also went into camp in Richmond Park, whence it was moved in July, 1915, to High Beech in Epping Forest, thence to Hare Hall, Romford, and finally to Berkhampstead, and on the absorption of the original 2nd Battalion by the 1st it was re-numbered 2/28th.[3] In May, 1915, instructions were issued for the formation within this Battalion of a separate School of Instruction for newly gazetted Officers of other Territorial regiments on similar lines to the School in France and during the next few months upwards of 1,500 such Officers passed through the School courses and examinations. In November, 1915, the Regiment was officially recognised by Army Order[4] as an Officers’ Training Corps, and the Home Battalion became the 2nd Artists Rifles O.T.C. In March, 1916, its separate School, then at Gidea Park, was converted into four Companies of cadets to which recruits were passed on for training as Officers after receiving a preliminary military training in the ranks of the other four Companies, the whole being under the command of Colonel Shirley and run by Artists’ Officers and Sergeant Instructors. In August, 1916, by which date the organisation of Officer Cadet Battalions throughout the United Kingdom had been perfected, the four Cadet Companies were separated from Colonel Shirley’s Battalion and transformed into “No. 15 (Artists Rifles), O.C.B.” which was placed under the command of Lt.-Col. E. St. L. Shaw (1st East Surrey) an invalided Regular Officer, with a Staff of Artists and other Officers and Sergeant Instructors. Thenceforth recruits enrolled in 3/28th were sent, on completion of their preliminary training, indiscriminately to No. 15 or to any other O.C.B. in which there were vacancies at the moment, while No. 15 as part of the general scheme of these O.C.B.’s received Cadets from other units besides the Artists.