Operation Astonia was the code name for an Allied attack on the German-held Channel port of Le Havre in France, during the Second World War.

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.

[2][3][a] On 6 July, Allied ships reported an "unusual object" passing through the Trout line, the eastern flank of the invasion area.

The Dambusters were followed by 228 more Lancasters and three hours later a second wave of 116 aircraft arrived, 1,880 long tons (1,910 t) of bombs hitting the port and anti-aircraft gun positions.

[9][8] Admiral Theodor Krancke, then Chief of Kriegsmarine Group Command West, called the raid a catastrophe and in the war diary wrote "It will be hardly possible to carry out the operations planned...since yesterday's attack on Le Havre".

[10] The Navy formed the Support Squadron Eastern Flank, a group of small gun-armed vessels, which came inshore during the day to bombard land targets and patrolled offshore at night.

[13] The Germans had dug an anti-tank ditch from the Lézarde valley past Montivilliers to the coast at Octeville-sur-Mer, covered by minefields, barbed wire and concrete defensive positions.

At the crest of the southern plateau, two fortified positions covered the town and port entrance and the Grand Clos coastal artillery battery could engage approaching ships.

[17][18][13] Near Fontaine La Mallet lay Strongpoint 8, with several concrete gun emplacements, the first of a series to cover the northern approaches to the port.

[19] Allied invasion plans required that the First Canadian Army (General Harry Crerar) on the left flank of the 21st Army Group (General Bernard Montgomery) should cross the Seine downstream of Rouen and turn left into the Le Havre peninsula to make right-handed flanking manoeuvres to capture Le Havre and its railway connections, Dieppe, Calais and Dunkirk, for the Allied supply effort.

[24] As the Canadian Army prepared its attack on Le Havre, the seaward approaches were blockaded closely by the Allies navies from 26 August; the port was the most westerly still in German possession and the Kriegsmarine tried to run supplies in and get out the ships still afloat.

[25] On 14 August 1944, Colonel Hermann-Eberhard Wildermuth took command of the fortress and later put the effective strength of the garrison at around 8,000 men, from a total of more than 11,000 personnel.

[18] Before the attack, the defenders were given an ultimatum and called upon to surrender; Wildermuth countered by requesting that civilians should be evacuated, given that his orders from Hitler were to hold Festung Le Havre to the last man.

[26] According to Wildermuth, many of the civilians were reluctant to leave, even when forced; some Resistance groups opposed evacuation, and there were concerns of a recurrence of the looting that had occurred in 1940.

On 10 September, about sixty bombers attacked the Grand Clos battery, followed by a bombardment from Warspite and Erebus, the combined efforts of which put the German guns out of action.

[29] During the North-west Europe Campaign (6 June 1944 – 8 May 1945), British specialist tanks were held in the 79th Armoured Division (Major-General Percy Hobart) and attached to other units for particular operations.

[33] In the I Corps plan, phase I had the 49th (West Riding) Infantry Division breaking through on the northern front capture strongpoints to the south and cross the Fontaine.

[35] The assault was costly for the specialised armour, the heavy rains making river banks much soggier than the plateaux, slowing flails and other vehicles at their most vulnerable.

[36] On the second day, the attack continued with support from Hawker Typhoons and armoured vehicles; facing the threat of Churchill Crocodile flame-throwing tanks, the last outer defence strongpoints surrendered at 14:00 hours.

[38] Wildermuth claimed that his lack of anti-tank guns had prevented a long defence of the port but other prisoners said that the Russian front was less of an ordeal than the bombing.

[43] On 11 September the Deputy G–4 for Movements and Transportation at SHAEF, Major General Charles Napier, recommended that Le Havre be assigned to the American Communications Zone (COMZ).

[45] It was the second largest port in France before the war, but it had been heavily damaged by German demolitions and Allied land, sea and aerial bombardment.

[47] The first Liberty ships entered the inner harbor on 19 September,[48] but sea mines and obstructions limited the docks to landing craft and coasters.