The Sledge Patrol: One of the Greatest Adventure Stories of World War II (1951).
The Shetland Bus: A WWII Epic of Escape, Survival, and Adventure (1951), together with "None but the brave" by Frithjof Sælen, later made into a movie called Shetlandsgjengen (aka. "Suicide Mission" in the USA). (Also published as Across to Norway)
Across to Norway (1952). (Also published as The Shetland Bus).
Thieves' Hole (1954).
We Die Alone: A WWII Epic of Escape and Endurance (1955), later made into a movie called Nine Lives (Norwegian: Ni Liv, 1957)
Dawn of D Day (1959) An account of the landing in Normandy, with many observations from participants.
The Shadow of the Dam (1961).
The Desert King: A Life Of Ibn Saud (1964).
Waterloo: A Near Run Thing (1968), analysis of the Battle of Waterloo, from the reports of those who fought it. (Published as "Waterloo: Day of Battle" in the USA (1968)).
Trafalgar: The Nelson Touch (1969), account of the Battle of Trafalgar, between the navies of France and Great Britain in 1805.
Sovereign of the Seas (1974), the story of British sea power.(pub. William Collins)
The Greek Adventure (1976), narrative describing the Greek War of Independence in the 1820s.
1066: The Year of the Conquest (1977), a historical narrative of the personalities and events of 1066 AD and how they changed Britain.
"The Dreadnoughts" (1979), A look at the development and use of battleship technology in World War 1.
Tahiti a Paradise Lost (1983), the decline of Tahiti, from its discovery by H.M.S.Dolphin in June 1767 (pub. Harvill Press)
Nelson: The Immortal Memory (1988), written with his son Stephen Howarth. It is a comprehensive biography of Britain's most famous Admiral.