The V-1, or to give it it's full name Vergeltungswaffe 1 (retaliation weapon 1) was an early predecessor of the cruise missile powered by a pulse-jet engine. It flew at 640 km/h (400 mph) and carried 180 kg of high-explosives to a range of 250km (160 miles).
Testing of the V-1 at Peenemünde continued until the night of the 17th/18th August 1943, when the RAF launched Operation Hydra, a raid against Peenemünde Army Research Center by 596 heavy bombers. The raid caused surprisingly little damage, though it set development at the facilities back by 6-8 weeks and resulted in the testing of the V-1 being moved to Brüsterort.
The V-1 was first launched against London on 17th June 1944, and launches continued against London and the south-east of England until the last launch sites in range were overrun in October 1944. Following this, they were launched against Antwerp and other Belgian targets. 9,521 were launched in total and they caused 22,892 casualties, almost entirely to civilians.
The successor to the V-1, the V-2 was the world's first true ballistic missile, and the grandfather to all modern rockets. The V-2 was the first man-made object in space, and when it's designers Wernher von Braun and Dr. Walter Dornberger fell into American hands after the war they were put to work developing their technology further. Von Braun later worked for NASA, and designed the Saturn V launch vehicle that propelled the Apollo spacecraft to the Moon.
The above video comes from the Romano Archives, and high-quality copies of the video along with thousands of other rare and interesting films are available from them.