His interest in military matters is not just a mere pastime, indeed in 1964, he enlisted into the Territorial Army, the part-time volunteer organisation of the British armed forces. Two years later he gained his commission. He spent most of his career in the Territorial Army with the 5th (Volunteer) Battalion, 5th (Volunteer) Battalion, The Queens Regiment, a NATO-centered infantry battalion.
Between 1969-85 he was a member of the Department of War Studies at the Royal Military Academy, Sandhurst, when he left to take command of the 2nd Battalion, The Wessex Regiment. He was promoted to Colonel when he chose to give up full-time service in 1986. In that same year, he was awarded the OBE (military) honour.
In 1990 he became Director of Cranfield University's Security Studies Institute. In February 1994, he was appointed Brigadier TA at Headquarters Land Command. In 1995 he was appointed Professor of Military and Security Studies.
From 1997 to 2000, he was Director Reserve Forces and Cadets, as well as having the distinguished honour of being Britain's senior serving reservist. In 1998, he was bestowed with another state honour, this time the CBE. In September 1999, he became Colonel of the Princess of Wales Royal Regiment (Queen's and Royal Hampshire). It's Colonel-in-Chief is Queen Margrethe II of Denmark.
He has written over a dozen books, from Firing Line to his latest book, Redcoat. His latest television work was a documentary series on the American Revolution and a Battlefield series concentrating on the bloody battles of WWII. His War Walks television series has been consistently repeated on British terrestial and digital television, such as BBC2 and UK History. One of his most compelling documentary series was Wellington: The Iron Duke, in which he chronicled the Dukes life, travelling to India, Waterloo and numerous other locations in a quest to truly reveal what the man was really like.