Second edition map of ‘Havre-Amiens' France is dated 1943 and shows the port city occupied by the Germans just East on the Normandy beaches landed on by the Allies on D-Day of June 6th, 1944. This map would have been used by the infantry soldier for moments and objective locations across France against the Germans.

Le-Harve is known for its part in Operation Astonia. Operation Astonia was the codename for an Allied attack on the German-held Channel port of Le Havre in France, during the Second World War. The city had been declared a Festung (fortress) by Hitler, to be held to the last man. Fought from 10 to 12 September 1944, the Allied objective was to secure the harbour facilities intact, to deliver supplies to the Allied armies in Continental Europe. The Allies refused to let the civilian population be evacuated, despite offers of free passage by the fortress commander. From 26 August, Royal Navy ships and Royal Air Force aircraft carried out a blockade and an extensive preparatory bombardment of the city, which killed over 2,000 civilians and 19 German troops. The land attack was carried out by the British 49th (West Riding) Infantry Division and the 51st (Highland) Infantry Division, aided by detachments of specialist armored vehicles from the 79th Armored Division, including Canadian troops. The German garrison of about 11,000 men surrendered on 12 September; the port was badly damaged but it was re-opened on 9 October. After the killing of so many French civilians, Allied commanders allowed the French inhabitants to leave Boulogne and other ports before attacking.

On D-Day, 6 June 1944, Allied troops landed in Normandy on the north coast of France in Operation Overlord and began the liberation of France. On D-Day, Allied aircraft laid a smoke screen off Le Havre to blind the coastal artillery; a torpedo-boat flotilla and a flotilla of patrol ships sailed from the port, using the smoke for camouflage. The German boats managed to fire 15 torpedoes off the Orne at 05:30, hit and sink HNoMS Svenner and forced several other ships to take evasive action. On 6 July, Allied ships reported an "unusual object" passing through the Trout line, the eastern flank of the invasion area. The object was fired on, launched a torpedo and sailed away. Several more objects appeared soon after, well dispersed and were also fired on. The devices managed to sink two minesweepers for a loss of nine sunk and fifteen losses from all causes of the 26 that had sailed from Le Havre; it was later found that they were Neger midget submarines of the K-Verband (Small Battle Units). On the night of 7/8 July, 21 Neger left Le Havre and all were sunk, most of their operators being killed, for one British minesweeper sunk and the Polish cruiser ORP Dragon damaged and scuttled off Sword Beach.