At 04.08 hours on the morning of 13 June 1944, two members of the Royal Observer Corps were on duty at their post on the top of a Martello tower on the seafront at Dymchurch in Kent. At that moment they spotted the approach of an object spurting red flames from its rear and making a noise like a Model-T-Ford going up a hill'. It was a development that they, and many others throughout the UK, had been anticipating for months. The first V1 flying bomb, an example of what Hitler had called his "Vergeltungswaffen" or Vengeance Weapons, to be released against Britain was rattling towards them. The two spotters on top of the tower may well have been aware that a new Battle of Britain had just begun. For years, key individuals in the UK had been aware of experiments by Germany to build long-range weapons. From leaked documents, reports from the French Resistance and the result of aerial photography a picture was gradually put together of an extensive programme by the Nazis to build pilotless aircraft, the Fi 103 V1 flying bomb, and the V2, the A4 rocket, which could be directed at the United Kingdom. By 1943, enough information had been gathered for Britain and its American allies to act, and the first bombing raids were undertaken against the long-range weapons installations. From August 1943, every effort was undertaken by the RAF and the USAAF Eighth Air Force to destroy every site lined to the V-weapons. This book, written by the Air Ministry's Air Historical Branch is the official account of the measures undertaken by the Air Defence of Great Britain, Fighter Command, Anti-Aircraft Command, Bomber Command and even the Balloon Command to defend the UK from what was potentially the greatest threat it had ever encountered. It was only through this multi-disciplinary approach that the actual effect of the V-weapons was contained to the level it was. Even so, the extent of the damage and deaths the flying bombs and rockets caused and the fear they generated, was considerable and had this coordinated approach not been undertaken the UK's resolve in the crucial months of the war might have been seriously challenged. This highly detailed, accurate and unbiased account is a valuable addition to the history of the Second World War. It demonstrates the difficulties the UK faced in identifying the nature of the highly secret German weapons and how, through an enormous combined effort, this threat was overcome. AUTHOR: This official account of the Allied campaign against the V-weapons was written for the Air Ministry and was based on information and testimonies provided by those involved in the campaign. 16 b/w illustrations