Middlebrook was educated at various schools, including a junior seminary for St Joseph's (Catholic) Missionary Society but left after less than two years. He then went to Ratcliffe College, Leicester, but left aged seventeen, having no wish to go to university. No qualifications. Intended a career as Merchant Navy officer but failed Board of Trade Eyesight Test through colour blindness.

Middlebrook worked at times as a potato merchant and as a poultry farmer, and was elected as a member of the British Egg Marketing Board representing six counties.

Local politics: He was a Member of Boston Borough Council and Mayor from 1966 to 1967) and a founder member Lincolnshire County Council.

National Service 1950-52. Would have been sent to Korea with Royal Leicesters but posted out of infantry because of colour blindness. Trained in Royal Artillery (RA), Oswestry. Commissioned Royal Army Service Corps (RASC). Served as Motor Transport Officer Suez Canal Zone and Aquaba, Jordan. General Service Medal, Suez Canal clasp. Three years Territorial Army service. 'Never heard a shot fired in anger.'

He wrote his first book The First Day on the Somme (1971) following a visit to the First World War battlefields of France and Belgium in 1967. This detailed study of the single worst day for the British Army remains a classic. Middlebrook gave the same single-day treatment to 21 March 1918, the opening of the German Spring Offensive, in The Kaiser's Battle.

Middlebrook's Second World War books concentrate on the air war. A number of them again deal with a single day of action (The Nuremberg Raid, The Schweinfurt-Regensburg Mission and The Peenemünde Raid) while others cover longer air battles (The Battle of Hamburg and The Berlin Raids).

Middlebrook also wrote two books on the Falklands War, one from the British and Falkland Islanders' perspective and one from the Argentine perspective.

Operated small battlefield touring business 1984-2004.

Middlebrook, born Boston, Lincolnshire 1932. Married Mary Sylvester of Boston, 1954, who provided assistance with all of his books. Three daughters - Jane living in Cheltenham, England (grandchildren Alice and Jessica); Anne in Calgary, Canada (grandchildren Jonathan and Melissa); Catherine in the South of France (grandchildren Rachel and Isobel).

An aunt, Miss Ettie Crick, present at the Battle of Mons (governess to a young girl at the Chadeau d'Hyon) remained in Belgium under German supervision until November 1918. An uncle, Teritoral Sergeant Andrew Crick, 1/4th Lincolns of the 46th (North Midland) Division, was fatally wounded in October 1915; buried Lijssenthoek Military Cemetery, near Poperinge. Another uncle, Private Charles Crick, 8th Gloucesters, 19th (Western) Division, gassed and prisoner-of-war in German Offensive March 1918. In his childhood, Middlebrook's mother, formerly Miss Crick, recounted many stories of her family's experiences in the First World War and that led him to a first visit to France with a friend, John Howlett, whose family also had First World War connections. That, in turn, led to his writing and research career and his interest in the battlefields.