Colonel De la Cherois T. Irwin was born in Carnagh County, Ireland, on 31 March 1843 and entered the Royal Militia Academy, Woolwich in early 1860. He was commissioned a 2nd Lieutenant in the Royal Artillery on 1 July 1861 and was posted to the 10th Brigade, then under order for duty in the West Indies.
Owing to the probability of war with the Northern States over the “Trent” affair, the brigade was diverted to Halifax. Irwin’s battery journeyed from Saint John, New Brunswick, to Montreal in sleighs during February 1862. He spent the next eight years at Montreal, Kingston and Quebec, marrying a lady from the latter city in 1867.
During these early years he studied hard at mastering his profession and gained the distinction of passing the entrance examination to the British Army Staff College, standing fourth in the entire British Army. Subsequently, he spent two years at Sandhurst. While at the College he was offered and accepted the appointment of Assistant Inspector of Artillery and Warlike Stores for the Dominion. He was posted to “A” Battery, the School of Gunnery at Kingston and promoted Major in the Canadian Militia. When Colonel French, the senior Inspector, left in 1873 to organize the North West Mounted Police, Major Irwin succeeded him as Commandant of the School of Gunnery and as Officer Commanding “A” Battery. In January 1876 he became Inspector of Artillery and Warlike Stores, an appointment shared with Lieutenant-Colonel Strange, and was promoted to Lieutenant-Colonel.
In 1878 he was called upon to erect the defensive works around Victoria and to organize a battery for defence. The arrival of a Russian Squadron in San Francisco harbour provided sufficient threat to stimulate immediate action; Britain immediately released a number of naval guns; the sites were laid out quickly, subsequently constructed and the Battery trained. The shortage of qualified assistants and his dependence on locally hired labour made personal supervision of each detail necessary. Within four months, one 8-inch, three 7-inch and four 64-pounders were installed and fifty men were trained and ready to man them.
In 1882 Lieutenant-Colonel Strange retired and Lieutenant-Colonel Irwin succeeded him to command all the Artillery of Canada. He retired from the Royal Artillery, came on strength of the Canadian Militia and simultaneously was appointed to the Headquarters Staff in Ottawa; je was now able to carry out a reform which had long been on his mind – the organization of the independent units of the Canadian Artillery into a single regiment. He served as the Regiment’s first Commanding Officer. It was through his efforts that the Canadian Artillery was granted the distinction “Royal” in 1882.
He also was responsible for other significant improvements: a better ration scale, the establishment of separate mess rooms, the preparation of rations by a Sergeant Cook, the expansion of the Royal Schools of Gunnery in Kingston and Quebec, the addition of a second Garrison Battery stationed at Quebec and the purchase of the Deseronto training area.
The Non-Permanent Force also benefited; he was instrumental in organizing the Canadian Artillery Association. This organization, the forerunner of all the militia associations, initiated a system of internal inspections and reforms which increased the efficiency greatly and esprit de corps of all Canadian Artillery units.
On 1 July 1897 he retired after twenty-five years service, fifteen years as head of the artillery. His career was not spectacular; his record of solid useful work, performed quietly and modestly with the good of The Regiment always foremost speaks for itself.
In retirement he continued to enjoy his lifelong activity as an artist and remained active in numerous philanthropic organizations. He introduced golf to Ottawa and it remained one of his favourite activities.
Colonel Irwin died in Washington at age eighty-five on 19 March 1928.