It is a tired old myth that Prime Minister Winston Churchill chose to ‘sacrifice’ (or to ‘martyr’) the city of Coventry rather than risk revealing the existence of the ‘Ultra’ code-breaking facility (Oxford Mail, September 22).

The facts, conveniently summarised in the Oxford Companion to the Second World War (page 275) and more fully set out in RV Jones, Most Secret War (Chapter 18) are these: It was indeed known well before November 14 that Coventry or some other Midland industrial city was about to be subjected to a major bombing, but not until 3pm that afternoon was Coventry discovered to be the one, the city over which the Luftwaffe’s direction beams were going to intersect.

Everything possible was then done to jam the beams and the raid that duly followed, but those things were not done well.

The electronic beam-jammers were incorrectly set and so proved useless, while the RAF managed to shoot down only one of more than 500 bombers sent out.

GEOFFREY BEST Buckingham Street Oxford