Over the centuries, proximity to major routes—the Great North Road, the Icknield Way, and Watling Street—has made Bedfordshire strategically important. Iron Age hillforts occupied significant locations, and castles consolidated Norman control after 1066. In later medieval times, two major events occurred: in 1224, the siege of Bedford Castle marked Henry III’s attempt to reimpose royal authority after the chaos of John’s reign; and the Second Battle of St Albans in 1461 was a major defeat for the Yorkists.

During the wars of the twentieth century, the county’s industrial base supported the armies fighting overseas. In the First World War, the county contributed significantly to the birth of the RAF as well as provided the base for the Home Defence armies. In the Second World War, its airfields despatched RAF and USAAF bombers over the continent, but the major activity was the secret war largely associated with the Bedford Triangle. After 1945, aeronautical research continued at RAF Thurleigh/Twinwood Farm and electronic intelligence-gathering was developed at Chicksands. ‘Defending Bedfordshire’ seeks to explain the significance of this dense concentration of military sites to be found in a relatively small county.