'Flashlamp' was the British series of air attacks by the bombers of Air Chief Marshal Sir Arthur Harris’s RAF Bomber Command against German artillery batteries on the Normandy coast as part of the Allied implementation of 'Overlord' (5/6 June 1944).
A total of 1,012 aircraft, in the form of 551 Avro Lancaster and 412 Handley Page Halifax heavy bombers, together with 49 de Havilland Mosquito light bombers, were despatched to bomb the batteries sited at Fontenay, Houlgate, La Pernelle, Longues, Maisy, Merville, Mont Fleury, Pointe du Hoc, Ouistreham and St Martin de Varreville, and of these 946 aircraft delivered their attacks.
Only the batteries at La Pernelle and Ouistreham were not obscured by cloud and were therefore bombed visually, while those at the other locations were bombed with the aid of 'Oboe' electronic navigation, and some 5,000 tons or more of bombs were dropped: this was the greatest single-night tonnage delivered by Bomber Command to date.
The British force lost three of its number in the form of two Halifax machines of No. 4 Group at Mont Fleury and one Lancaster of No. 6 Group at Longues.