The V-2 was the first ballistic missile used in warfare and a significant advancement in rocket technology. Also known as the A4, it was developed by Nazi Germany during World War II and used against the Allies, primarily as a terror weapon. Because it was so inaccurate (it could barely hit a city-size target), it could not be used against specific military targets and was instead used against civilians who had no defense against it as it came screaming down from the upper atmosphere. Adolf Hitler named it his "Vengeance Weapon 2"or "V-2" because it wreaked vengeance upon a helpless population. (The "Vengeance Weapon 1," or "V-1", was a cruise missile.)