The technical marvel that was Hitler's "wonder weapon"

On 13 June 1944, residents of London woke up to the first of many attacks on their city by Germany's V-1. The pilotless aircraft - one of the "wonder weapons" that Hitler's generals promised - killed eight civilians upon impact. This was just the beginning. A couple of days later, the Germans launched 244 V-1's, hitting areas in and around London.

The weapon, which became known in the press as the "buzz bomb" because of its distinctive sound, was actually called Vergeltungswaffe 1 (Revenge Weapon No 1). It measured 25 feet in length and could carry 2,000 pounds of explosives. By the end of the war, it was able to fly as far as 250 miles to targets in England from launch sites in Holland and France. More than 9,000 got launched before Allied forces were able to overrun the launch sites.

A profile picture of the V-1, which was launched just a week after Allied forces stormed the beaches of Normandy. It took less than a half hour for the flying bombs to reach London.

The V-1 was designed to be a terror weapon. Although the majority of the launches were unsuccessful, the flying rocket killed still caused nearly 23,000 civilian casualties by war's end. And despite their lack of accuracy, the V-1s nonetheless managed to hit 176 factories, 141 railroad bridges, 146 public utilities and 57 military installations between June and September 1944, according to Benjamin King, Timothy Kutta, co-authors of "Impact: The History Of Germany's V-weapons In World War 11.

Partly in reaction to a relentless bombing campaign waged by the Allies against V-1 launch site, the Germans figured out how to launch the V-1from modified Heinkel airplanes. The process was relatively straightforward with the Heinkel dropping the V-1, which would drop a few hundred feet before gaining enough power from its pulse jet engine to take it to the target.

Rare photo of a British Spitfire using its wingtip to knock a V-1 flying bomb off course. This was a fortunate interception as the V-1s were usually too fast to hit with anti-aircraft fire.

German factories manufactured nearly 30,000 V-1s by the end of the war. Here's a topic of speculation that has tickled historians since the end of WW2. Had Allied armies failed in their invasion of France, England would have continued to suffer from launches of robot missiles - which presumably would have grown in distance and lethality.

The remains of a V-1 launch site in France.

A plaque at Grove Road, Mile End in London honoring the victims who died in the first-ever V-1 attack