Source: Michael Doyle Their Name Liveth For Evermore: The Great War Roll of Honour for Leicestershire and Rutland.
He was the son of William Clarke a hosiery commercial traveller, born 1841 in Hinckley, Leics., and his late wife, Mary Jemima (Minnie) Clarke (nee Cosbey), born 1846 in Southam, Halifax,Yorks., and who was the daughter of George Cosbey a school master, born 1823 in Armagh, Ireland and his wife Jemima, born 1821 in Brixton, Surrey. Harry Cosbey Clarke was born in 1887 in Leicester, his siblings were, William Casper Clarke, born 1871, Minnie L., born 1875, Beatrice E., born 1879 and Gertrude A., born 1880, all his siblings were born in Leicester, in April 1891 the family home was at 47, Upper Tichborne Street, Leicester. Harry was the husband of Margaret Clarke. On the 31st January 1920 the Wyggeston Grammar School for Boys in Leicester published a Roll of Honour of former pupils, this shows that Henry attended the school in 1899. His enlistment documents show that he gave his trade or calling as Salesman, and his next of kin as his wife Margaret of 341, Queen Street, St. James, Winnipeg, Manitoba, Canada. He stated that he belonged to the Active Militia, the 106th Regiment at the time of his enlistment, and had previously served with the Corps Guides for 6 months and the Canadian Reserve Militia Regiment for 3 years. His medical examination records that he was 5 foot 10 inches in height and had a chest measurement of 34 to 37 inches, his complexion was described as dark with blue eyes and dark hair, it was noted that he had a mole on the back of his left shoulder. He gave his religion as Church of England. His enlistment documents show three service numbers, 460278, 460686 and 460687.