Source: Michael Doyle Their Name Liveth For Evermore: The Great War Roll of Honour for Leicestershire and Rutland.
He was the son of John and Elizabeth Sibson of Wigston Magna, Leics., he was one of four sons, his brothers being Leonard, Cecil and Oliver. The four boys were all born at The Craddock Arms in Knighton, where their parents at the time managed the business. Before the outbreak of war Douglas had emigrated to Canada to join his brother Leonard, and whilst there enlisted in the 1st Canadian Mounted Rifles. His enlistment documents record that he gave his trade or calling as Farmer, and his next of kin as his father, John Sibson of Leicester Road, Wigston, Leicestershire, England. He stated that he was unmarried, and that he had previously served 2 years with the Leicestershire Yeomanry. Information taken from his medical examination shows that he was 5 foot 6 ¼ inches in height and had a chest measurement of 33 to 34 ½ inches. His complexion was described as fresh with blue eyes and dark brown hair. He gave his religion as Church of England.