ULTRA and the Coventry Blitz

On the night of 14th Nov 1940, during the height of the British Blitz, the City of Coventry succumbed to great devastation which resulted in over 500 deaths and the complete destruction of Coventry Cathedral. The German raid had lasted for over 10 hours as Luftwaffe aircraft unloaded mercilessly on the innocent civilians below.

Prior to the Coventry raid, the possibility of a severe attack against Britain seemed like a genuine possibility to Churchill. This was so much so that Britain was placed on a stand by alert phase under the code name Cromwell, symbolising Britain’s preparation in air defences in an attempt to deter German raids. The Coventry raid was later revealed to be part of a three phase attack against Britain named Moonlight Sonata. Moonlight Sonata is since thought to have been a reaction from Germany after they had failed to invade British shores by the end of 1940.


ULTRA was the designation adopted by British Intelligence during the early years of the Second World War, tasked with breaking the enemy’s encryptions and ciphers in the hope of aiding the war effort. Sources at the time claim that ULTRA had informed Churchill of the forthcoming Moonlight Sonata attack culminating in the supposed Coventry Myth, yet the officers working for ULTRA at Bletchley Park had no such information.

In actual fact the most feasible way Britain was able to gather any warning of the Coventry Blitz never came from military intelligence at all. A full three days prior to the attack, a German prisoner of war had been shot down claiming that he knew of a “colossal raid” that was to take place under the designation Moonlight Sonata. The exact location of Coventry was still unknown however.

coventry-blitz devastation

Operation Moonlight Sonata commenced on the following day at 1900 hrs, with two thirds of the city having been damaged. In one night almost 4,500 homes were destroyed. A statement made by the minister of aircraft production claimed that despite the degree of damage the city was still able to function with the main structure of the electric supply remaining.

Aaron Potter

Aaron Potter

Hello I’m Aaron and like most other people you’ll find on this website I love writing about history, so much that I chose to study it in my home city of Bristol. There is only one past but many histories, and it’s in researching these histories which gets me pumped as I discover a possible untold story. When I’m not trudging through archives or writing about the past, you can find me sharing my thoughts about all things gaming related at www.rockingameskid.blogspot.co.uk and critiquing movies and movie news on my weekly podcast www.thepictureblock.com.