The raid took place on the northern coast of France on 19 August 1942. The assault began at 5:00 a.m. and by 10:50 a.m. the Allied commanders were forced to call a retreat. Over 6,000 infantrymen, predominantly Canadian, were supported by limited Royal Navy and large Royal Air Force contingents.
The objective of the raid was discussed by Churchill in his war memoirs: "I thought it most important that a large-scale operation should take place this summer, and military opinion seemed unanimous that until an operation on that scale was undertaken, no responsible general would take the responsibility of planning the main invasion". Churchill continues:
In discussion with Admiral Mountbatten it became clear that time did not permit a new large-scale operations to be mounted during the summer (after Rutter had been cancelled), but that Dieppe could be remounted (the new code-name "Jubilee") within a month, provided extraordinary steps were taken to ensure secrecy. For this reason no records were kept but, after the Canadian authorities and the Chiefs of Staff had given their approval, I personally went through the plans with the C.I.G.S., Admiral Mountbatten, and the Naval Force Commander, Captain J. Hughes-Hallett.
Objectives included seizing and holding a major port for a short period, both to prove it was possible and to gather intelligence from prisoners and captured materials, while assessing the German responses. The Allies also wanted to destroy coastal defences, port structures and all strategic buildings…. No major objectives of the raid were accomplished. A total of 3,623 of the 6,086 men (almost 60%) who made it ashore were either killed, wounded, or captured. The Royal Air Force failed to lure the Luftwaffe into open battle, and lost 96 aircraft (at least 32 to flak or accidents), compared to 48 lost by the Luftwaffe. The Royal Navy lost 33 landing craft and one destroyer….
Dieppe, a coastal town in the Seine-Maritime department of France, is built along a long cliff that overlooks the English Channel. The River Scie is on the western end of the town and the River Arques flows through the town and into a medium-sized harbour. In 1942, the Germans had demolished some seafront buildings to aid in coastal defence and had set up two large artillery batteries at Berneval-le-Grand and Varengeville. One important consideration for the planners was that Dieppe was within range of the Royal Air Force's fighter aircraft….
The Dieppe landings were planned on six beaches: four in front of the town itself, and two to the eastern and western flanks respectively…. Intelligence on the area was sparse: there were dug-in German gun positions on the cliffs, but these had not been detected or spotted by air reconnaissance photographers. The planners had assessed the beach gradient and its suitability for tanks only by scanning holiday snapshots, which led to an underestimation of the German strength and of the terrain…. The German forces at Dieppe were on high alert having been warned by French double agents that the British were showing interest in the area. They had also detected increased radio traffic and landing craft being concentrated in the southern British coastal ports.
Dieppe and the flanking cliffs were well defended. The 1,500-strong garrison from the 302nd German Infantry Division comprised the 570th, 571st and 572nd Infantry Regiments, each of two battalions, the 302nd Artillery Regiment, the 302nd Reconnaissance Battalion, the 302nd Anti-tank Battalion, the 302nd Engineer Battalion and 302nd Signal Battalion. They were deployed along the beaches of Dieppe and the neighbouring towns, covering all the likely landing places. In respect to machine guns, mortars and artillery, the city and port was adequately protected with a concentration on the main approach (particularly in the myriad of cliff caves), and with a reserve at the rear….
The Allied fleet left the south coast of England on the night of 18 August 1942, preceded by minesweepers that cleared paths through the English Channel for them. The fleet included eight destroyers, motor gun boats who escorted the landing craft and motor launches. The initial landings began at 04:50 on 19 August, with attacks on the two artillery batteries on the flanks of the main landing area….
One of the objectives of the Dieppe Raid was to discover the importance and accuracy of a German radar station on the cliff-top to the east of the town of Pourville. To achieve this, RAF Flight Sergeant Jack Nissenthall, a radar specialist, was attached to the South Saskatchewan Regiment. He was to attempt to enter the radar station and learn its secrets, accompanied by a small unit of 11 men of the Saskatchewans as bodyguards. Nissenthall volunteered for the mission fully aware that, due to the highly sensitive nature of his knowledge of Allied radar technology, his Saskatchewan bodyguard unit were under orders to kill him if necessary to prevent him being captured. He also carried a cyanide pill as a last resort…. Nissenthall and his bodyguards failed to enter the radar station due to strong defences, but Nissenthall was able to crawl up to the rear of the station under enemy fire and cut all telephone wires leading to it. This forced the crew inside to resort to radio transmissions to talk to their commanders, transmissions which were intercepted by listening posts on the south coast of England. The Allies were able to learn a great deal about the arrays of German radar stations along the channel coast thanks to this one simple act, which helped to convince Allied commanders of the importance of developing radar jamming technology. Of this small unit, only Nissenthall and one other returned safely to England….
Of the nearly 5,000 strong Canadian contingent deployed that early August morning, 3,367 were killed, wounded or taken prisoner; an exceptional casualty rate of 68%. The British Commandos had lost 247 men. The Royal Navy lost one destroyer (HMS Berkeley) and 33 landing craft, suffering 550 dead and wounded. The RAF lost 106 aircraft to the 48 lost by the Luftwaffe. The German Army’s casualties totalled no more than 591…. The commanding officers who designed the raid on Dieppe had not envisioned such losses. This was, after all, one of the first attempts by the Allied faction on a German-held port city. As a consequence, planning from the highest ranks in preparation for the raid was minimal. Critical strategic and tactical errors were made which resulted in scores of Allied (particularly Canadian) deaths…