Norman was born September 11th, 1893 to David and Catherine Harvey (nee Greenlees) Colville. He was educated at Fettes School, Edinburgh, and at Clare College, Cambridge University. He fought in the First World War, where he was mentioned in despatches twice and being awarded the Military Cross (M.C.). He married, Marjorie Southworthe Edelston, daughter of Philip Edelston, on 10 November 10th, 1915 and together they had two children, Anne Lindsay b. August 1st, 1916, and Gavin David b. June 20th, 1922. He retired from the military in 1919, with the rank of Captain, late of the Argyll and Sutherland Highlanders. In 1920, he purchased the Penheale Manor and Estate at Egloskerry.
Marjorie was tragically killed in a car accident on October 26th, 1937. On July 14th, the following year, he re-married to André Manuela Alexandre Joaquina Bapst, daughter of Constant Germain Bapst, but she too died, passing away on May 8th, 1940. By this time, with the Second World War ravaging the country, Norman gained the rank of Group Commander in 1940 in the Home Guard. He also held the office of High Sheriff of Cornwall between 1940 and 1941. More tragedy was to strike the family, when in November 1941, his son Gavin, now serving as a pilot with the R.A.F., was killed in action whilst fighting at Tripoli, Libya. He was interred in the Municipal Cemetery at Tripoli. On June 1st, 1951, Norman again re-married, this time to Diana Evelyn Legh, daughter of Lt.-Col. Hon. Sir Piers Walter Legh. The following year, on April 16th, they had a son, James Charles David. Norman passed away on August 26th, 1974, aged 80 and was interred at Egloskerry Church. Diana survived him by 26 years, herself passing away on November 11th, 2000.