He was grandson of the Hon. Enos Collins, M.L.C., of Gorse Brook, Halifax, and great-grandson of Sir Brenton Haliburton, Chief Justice of Nova Scotia. He was educated at Galt Collegiate Institute, Ontario, and at the Picton Academy, from whence he passed into the Royal Military College, Kingston, Canada, in 1883. He joined the Royal Irish Rifles as a Lieutenant in September, 1885, going with them to Gibraltar in 1886, and on to Egypt in 1888. He took part in the Nile Campaign in 1889, but, contracting smallpox at Assouan, he was sent home to recover, and spent two years at the Depot at Belfast, rejoining his battalion in Malta. He was promoted Captain in 1893, and when the Rifles came back to home service he obtained an Adjutancy of Volunteers in Devonshire in October, 1896, and from that date until March, 1901, by ceaseless energy he brought the battalion to full strength and high efficiency. In March, 1901, he was appointed a special service officer, including the command of a mounted infantry battalion for the South African War. He was present at operations in the Transvaal, Orange River Colony, and Cape Colony, between April, 1901, and May, 1902, having been Mentioned in Despatches for his services (London Gazette, July 29th, 1902), also receiving the Queen's Medal with five clasps. After peace was signed he served in Ireland, and in October, 1904, obtained his majority. Afterwards he served in England till, becoming Lieut.-Colonel in 1912, he went out to India to take command of the 1st Battalion Royal Irish Rifles. He was deeply engaged at this time in writing the History of his Regiment, a work soon officially accepted and highly praised. He had previously written a history of "The French in Morocco," compiled from many sources during his years in the Mediterranean. When the European War broke out in August, 1914, he was at Aden with his battalion, and until anxiety in Somaliland was allayed the Irish Rifles were detained there, only reaching France in November. They spent the winter in the trenches, taking their share in the fierce fighting in December. On March 10th, 1915, they took part in the attack on Neuve Chapelle, and were the first battalion to reach the village, but losses were heavy. A sergeant-major wrote: "Our Colonel was everywhere, encouraging his men, and seeming to bear a charmed life. He knew no fear, and walked quietly in front of us as if no bombardment were going on." On Friday evening, March 12th, a fresh assault was ordered. Lieut.-Colonel Laurie rallied his exhausted men, and, calling out "Follow me! I will lead you!" he sprang over the parapet, revolver in hand. A moment later he fell shot through the head. He was buried with his fallen officers and men in a garden near Neuve Chapelle. During this war he was twice Mentioned in Despatches (_Gazette_, January 14th, 1915; and after his death, May 31st, 1915).