The raid that began on the evening of 14 November 1940 was the most severe to hit Coventry during the war. It was carried out by 515 German bombers, from Luftflotte 3 and from the pathfinders of Kampfgruppe 100. The attack, code-named Operation Mondscheinsonate (Moonlight Sonata), was intended to destroy Coventry's factories and industrial infrastructure, although it was clear that damage to the rest of the city, including monuments and residential areas, would be considerable.
The first wave of follow-up bombers dropped high explosive bombs, knocking out the utilities (the water supply, electricity network and gas mains) and cratering the roads, making it difficult for the fire engines to reach fires started by the follow-up waves of bombers. The follow-up waves dropped a combination of high explosive and incendiary bombs. There were two types of incendiary bomb: those made of magnesium and those made of petroleum. The high explosive bombs and the larger air-mines were not only designed to hamper the Coventry fire brigade, they were also intended to damage roofs, making it easier for the incendiary bombs to fall into buildings and ignite them
Coventry's air defences consisted of twenty four 3.7 inch AA guns and twelve 40mm Bofors. Over 6,700 rounds were fired. However only one German bomber was shot down.[20]
In one night, more than 4,000 homes in Coventry were destroyed and around two-thirds of the city's buildings were damaged. The raid was heavily concentrated on the city centre, most of which was destroyed. Two hospitals, two churches and a police station were also among the damaged buildings.[21].[22] Around one third of the city's factories were completely destroyed or severely damaged, another third were badly damaged, and the rest suffered slight damage.
The raid reached such a new level of destruction that Joseph Goebbels later used the term Coventriert ("Coventrated") when describing similar levels of destruction of other enemy towns. During the raid, the Germans dropped about 500 tonnes of high explosives, including 50 parachute air-mines, of which 20 were incendiary petroleum mines, and 36,000 incendiary bombs.[25]
The raid of 14 November combined several innovations which influenced all future strategic bomber raids during the war.[26] These were:
-The use of pathfinder aircraft with electronic aids to navigate, to mark the targets before the main bomber raid.
-The use of high explosive bombs and air-mines (blockbuster bombs) coupled with thousands of incendiary bombs intended to set the city ablaze in a firestorm.
In the Allied raids later in the war, 500 or more heavy four-engine bombers all delivered their 3,000–6,000 pound bomb loads in a concentrated wave lasting only a few minutes. But at Coventry, the German twin-engined bombers carried smaller bomb loads (2,000–4,000 lb), and attacked in smaller multiple waves. Each bomber flew several sorties over the target, returning to base in France to rearm. Thus the attack was spread over several hours, and there were lulls in the raid when fire fighters and rescuers could reorganise and evacuate civilians.[27] As Arthur Harris, commander of RAF Bomber Command, wrote after the war "Coventry was adequately concentrated in point of space [to start a firestorm], but all the same there was little concentration in point of time".[28]