Operation Diver was Britain's air defense campaign against the V1 flying bomb towards the end of World War II. It was a multi-faceted operation, mainly involving fighter aircraft, barrage balloons, searchlights, and anti-aircraft guns. Although a great deal has been written about the V1, studies of the action have been dominated by the fighter aircraft of the RAF, at the expense of the gunners of Anti-Aircraft Command. Their sources, to a great extent, have remained unconsulted, and their story untold. Yet the Diver campaign was unquestionably their greatest achievement of the war. No other episode in Britain's domestic wartime history resembled its particular mix of concentration and scale, nor its focus on a single, wholly new weapon, and its breadth of innovation and technological change. In Diver, Anti-Aircraft Command was required to transform itself from a static and (by 1944) somewhat under-employed arm of the defense into a quasi-mobile, reactive force, facing a fearsome weight of attack by continual adaptation and technical and tactical change. Most of Diver's senior commanders were members of the Territorial Army (TA)--bankers, lawyers, engineers: loyal part-time stalwarts who had kept AA artillery alive in the inter-war years.

Diver was a campaign of first-rank military importance, fought out over a battlefield from the Kentish Weald to the southern, East Anglian, and Yorkshire coasts. Tens of thousands of people were involved, hundreds of guns, and well over one thousand individual sites. Yet for a variety of reasons--portable equipment, movement, transitory occupation, post-war development--the campaign's physical legacy is minimal. We look practically in vain for Diver's remains today: the shattered concrete, twisted metal, and crumbling brick which characterize so much World War II infrastructure 70 years after the event are, here, almost nowhere to be found. Militarily, Operation Diver was a battle won; but also, in this sense, a battle subsequently lost.