'Mondscheinsonate' was the German air attack on Coventry (14/15 November 1940).

At the start of World War II, Coventry was a major industrial city of around 238,000 persons and, like much of the industrial West Midlands region of the UK, contained metal and wood-working industries. In Coventry’s case, these included cars, bicycles, aero engines and, since 1900, munitions factories. During World War I, the advanced state of the mechanical tooling industry in the city had meant that pre-war production could quickly be turned to the manufacture of items for military purposes in facilities such as the Coventry Ordnance Works, which became one of the leading British munition-manufacturing centres and completing some 25% of all British aircraft produced during that war.

Like many of the industrial cities and towns of the West Midlands that had been industrialised during the Industrial Revolution, many of the small- and medium-sized factories in the city were woven into the same streets as the workers' houses and the shops of the city centre. However, in the period between the two world wars Coventry developed many large suburbs of both private and council housing, which were relatively isolated from industrial buildings. The city was also at the centre of the UK’s car industry, with many carmakers based at different parts of the city, although many of these factories had switched to help supply the war effort.

The Germans made 17 small raids on Coventry during the Battle of Britain between August and October 1940: in the course of these raids about 198 tons of bombs were dropped. These raids killed a total of 176 persons and injured about 680. The most notable physical damage was to the new Rex Cinema, which had been opened in February 1937 and had already been closed by an earlier bombing raid in September.

On 17 October, 2^nd Lieutenant Sandy Campbell of the Royal Engineers Bomb Disposal Company was called upon to deal with an unexploded bomb that had fallen at the Triumph Engineering Company’s works in Canley. War production in two factories had ceased on a temporary basis because of this, and many nearby residents had been evacuated.

The 'Mondscheinsonate' 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 bombers of Generalfeldmarschall Hugo Sperrle’s Luftflotte III and the specialised pathfinder aircraft of Hauptmann Kurt Aschenbrenner’s Kampfgruppe 100. The 'Mondscheinsonate' 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 initial wave of 13 specially modified Heinkel He 111 aircraft of Kampfgruppe 100, which were equipped with X-Gerät navigational equipment, accurately dropped marker flares at 19.20. The British and the Germans were currently fighting the 'Battle of the Beams', but on this night the British failed to disrupt the X-Gerät signals.

The first wave of follow-up bombers dropped HE bombs, knocking out much of the city’s utilities such as the water supply, electricity network, telephones and gas mains, and cratering many of the roads, making it difficult for the fire engines to reach fires started by the later waves of bombers. These later waves dropped a combination of HE and incendiary bombs. Of the latter there were two types: those made of magnesium and those made of petroleum. The HE bombs and the larger air mines not only hindered the efforts of Coventry’s fire brigade, but were also intended to damage roofs, making it easier for the incendiary bombs to fall into and then ignite buildings.

Coventry’s air defences at this time comprised 24 3.7-in (94-mm) anti-aircraft guns and 12 40-mm Bofors guns. The AA Defence Commander of 95^th (Birmingham) Heavy Anti’Aircraft Regiment had readied a series of concentrations to be fired using sound locators and GL Mk I gun-laying radar, and 128 concentrations were fired before the bombing severed all lines of communication and the noise drowned out sound-location. The anti-aircraft batteries then fought in isolation. Some gun positions were able to fire at searchlight beam intersections, glimpsed through the smoke and estimating the range. Although the Coventry guns fired 10 rounds per minute for the whole 10-hour raid, for a total of more than 6,700 rounds, there shot down only one German bomber.

At about 20.00, Coventry’s mediaeval cathedral was hit and set on fire by incendiaries for the first time. The volunteer firefighters managed to put out the first fire, but other direct hits followed and new fires quickly broke out in the cathedral. Accelerated by a firestorm, the flames quickly spread out of control. During the same period, more than 200 other fires were started across the city, most of which were concentrated in the area of the city’s centre, setting the area ablaze and overwhelming the firefighters. The telephone network was crippled, hampering the fire service’s command and control and making it difficult to prioritise the firefighters' efforts. As the Germans had intended, the water mains were also damaged by HE bombs, meaning that there was not enough water available to tackle many of the fires. The raid reached its climax around midnight, and the 'all clear' signal sounded at 06.15 on the morning of 15 November.

In just the single night, more than 4,300 homes in Coventry had been destroyed and about two-thirds of the city’s buildings 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 damaged. The local police force lost nine constables or messengers during the attack. About one-third of the city’s factories were completely destroyed or severely damaged, another third were badly damaged, and the rest suffered slight damage. Among the destroyed factories were the main Daimler factory, the Humber Hillman factory, the Alfred Herbert Ltd machine tool works, nine aircraft factories, and two naval ordnance stores. However, the effects on war production were only temporary, as much essential war production had already been moved to 'shadow factories' on the city outskirts. Also, many of the damaged factories were quickly repaired and had recovered to full production within a few months.

It was estimated that 568 people were killed in the raid (the exact figure was never precisely confirmed), with another 863 badly injured and 393 sustaining lesser injuries. Given the intensity of the raid, casualties were limited by the fact that a large number of Coventry’s citizens left the city at night to sleep in nearby towns or villages following the earlier air raids. Also, people who took to air raid shelters suffered very little death or injury. Out of 79 public air raid shelters holding 33,000 people, very few had been destroyed.

Although it was the city centre which suffered the worst of the attack, districts of the city including Stoke Heath, Foleshill and Wyken were also heavily bombed.

The raid had reached a level of destruction so novel and so great that Joseph Goebbels, the German minster of propaganda, later used the term coventriert ('coventried') when describing similar levels of destruction of other towns. During the raid, the Germans dropped about 500 tonnes of HE bombs (including 50 parachute mines), of which 20 were incendiary petroleum mines, and 36,000 incendiary bombs.

The raid of 14/15 November combined several innovations which influenced all future strategic bomber raids during the war. These included the use of pathfinder aircraft with electronic aids to navigate, and to mark the targets before the main bomber raid; and the use of HE bombs and air mines in combination 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-engined bombers all delivered their 3,000- to 6,000-lb (1360- to 2720-kg) bomb loads in a concentrated wave lasting only a few minutes. But at Coventry, the German twin-engined bombers carried smaller bomb loads, in the order of some 2,20o to 4,400 lb (1000 to 2000 kg), and attacked in several smaller waves. Each bomber flew several sorties over the target, returning to base in France to rearm. Thus the attack was spread over several hours: there were thus lulls in the raid when firefighters and rescuers could reorganise and evacuate civilians.

The British exploited the opportunity given them by 'Mondscheinsonate' to try a new tactic against Germany. This was the 'Abigail Rachel' undertaking of 16 December against Mannheim. The British had been awaiting the opportunity to experiment with an incendiary-intensive raid, and saw this as a kind of retaliation for the German raid on Coventry, and marked the beginning of a British movement away from precision attacks on military targets toward area bombing attacks on whole cities.

In a book of 1974, The Ultra Secret, Group Captain F. W. Winterbotham asserted that the British government had advance warning of the attack from 'Ultra' interception of German radio traffic encrypted with the Enigma cipher machine and decoded by British cryptanalysts at Bletchley Park. He further claimed that Prime Minister Winston Churchill had ordered that no defensive measures should be taken to protect Coventry, lest the Germans suspect that their cipher had been broken. Winterbotham was a key figure for 'Ultra' and supervised the 'Special Liaison Officers' system for the delivery of 'Ultra' material only to the most senior and fully authorised field commanders. Winterbotham’s assertion has been rejected by other 'Ultra' participants and historians, however, these stating that while Churchill was indeed aware that a major bombing raid would take place, no one knew what the target would be.

On the night of 8/9 April 1941 Coventry was again raided, I this instance by 230 bombers which dropped 315 tons of HE bombs and 25,000 incendiaries. In this and another raid two nights later, some 451 people were killed and more than 700 seriously injured. Damage was caused to many buildings including some factories, the central police station, the Coventry & Warwickshire Hospital, King Henry VIII School, and St Mary’s Hall. The main architectural casualty of the raid was Christ Church, most of which was destroyed, leaving only the spire.

The last air raid on Coventry was delivered on 3 August 1942, in the Stoke Heath district about 1 mile (1.6 km) to the east of the city centre. Six people were killed. By the time of this air raid, some 1,236 people had been killed by air raids on Coventry; of these, 808 rest in the mass grave in London Road Cemetery. About 80% of them had been killed in the raids of 14/15 November 1940 and 8/10 April 1941.

An immediate start on reconstruction was undertaken by a committee headed by the motor industry magnate William Rootes.