Born in 1885, son of Joshua Harris from Wolverton, Buckinghamshire and Louisa Allen from Charlbury, Oxon. The family were living on High Street, Wheatley between 1891 and 1911. Gilbert was attending Wheatley Elementary school in 1892. In 1901 he was listed as grocer's assistant: this was in Harris' Shop and General Store of which his father was proprietor. The store sold some medication for people unable to pay for the doctor, and Joshua Harris was also known for his ability to extract teeth. (Sisters of both Charles Jennings and Archibald Harding worked in the Harris household.) By 1911 Gilbert was working as an assistant to an ironmonger and was lodging in Tunbridge Wells, Kent. He married that same year.