Operation Epsom, also known as the First Battle of the Odon, was a British offensive in the Second World War between 26 and 30 June 1944, during the Battle of Normandy. The offensive was intended to outflank and seize the German-occupied city of Caen from the west, an important Allied objective, in the early stages of Operation Overlord, the Allied invasion of north-west Europe.

Preceded by Operation Martlet to secure the right flank of the advance, Operation Epsom began early on 26 June, with units of the 15th (Scottish) Infantry Division advancing behind a creeping artillery barrage. Air cover was sporadic for much of the operation, because poor weather in England forced the cancellation of bomber support. Accompanied by the 31st Tank Brigade, the 15th (Scottish) Infantry Division made steady progress and by the end of the first day had overrun much of the German outpost line, although some difficulties remained in securing the flanks. In mutually-costly fighting over the following two days, a foothold was secured across the River Odon and efforts were made to expand this, by capturing tactically valuable points around the salient and moving up the 43rd (Wessex) Infantry Division. By 30 June, after German counter-attacks, some of the British forces across the river were withdrawn and the captured ground consolidated, bringing the operation to a close.

Many casualties were suffered by both sides but unlike General Bernard Montgomery, the Allied commander in Normandy, Generalfeldmarschall Erwin Rommel was unable to withdraw units into reserve after the battle, as they were needed to hold the front line. The British retained the initiative, attacked several more times over the following two weeks and captured Caen in Operation Charnwood in mid-July. Interpretations of the intention and conduct of Operation Epsom differ but there is general agreement concerning its effect on the balance of forces in Normandy. The Germans contained the offensive but only by committing all their strength, including two panzer divisions just arrived in Normandy, which had been intended for an offensive against Allied positions around Bayeux.

Background Operation Overlord called for the British Second Army (Lieutenant-General Miles Dempsey), to secure the Caen and then form a front line from Caumont-l'Éventé to the south-east of Caen. The intention was to acquire space for airfields and to protect the left flank of the US First Army (Lieutenant General Omar N. Bradley), while it fought the Battle of Cherbourg. A section of the full British Army Order No 1 transcript (I Corps Operations Order No. 1, WO 171/258) read,

Possession of Caen and its surroundings would give the Second Army a suitable staging area for a push south to capture Falaise, which could be used as the pivot for a swing left to advance on Argentan and then towards the Touques River. Hampered by congestion in the beachhead, which delayed the deployment of its armoured support and forced to divert effort to attack strongly held German positions along the route to the town, the 3rd Infantry Division was unable to assault Caen in force on D-Day and was stopped short by the 21st Panzer Division. Follow-up attacks failed as German reinforcements arrived. Abandoning the direct approach, Operation Perch—a pincer attack by I and XXX Corps—was launched on 7 June, to encircle Caen from the east and west.

I Corps, striking south out of the Orne bridgehead, was halted by the 21st Panzer Division and the attack by XXX Corps west of Caen was stopped in front of Tilly-sur-Seulles by the Panzer-Lehr-Division. To force Panzer-Lehr to withdraw or surrender and to keep operations fluid, part of the 7th Armoured Division pushed through a gap in the German front line near Caumont and captured Villers-Bocage. The Battle of Villers-Bocage led to the vanguard of the 7th Armoured Division being ambushed and withdrawing from the town but by 17 June, Panzer Lehr had also been forced back and XXX Corps had taken Tilly-sur-Seulles.

Another attack by the 7th Armoured Division and other offensive operations were abandoned when a severe storm descended on the English Channel on 19 June. The storm lasted for three days and further delayed the Allied build-up. Most of the convoys of landing craft and ships already at sea were driven back to ports in Britain; towed barges and other loads (including of floating roadways for the Mulberry harbours) were lost and 800 craft were left stranded on Normandy beaches until the spring tides in July.

Planning began for a second offensive, Operation Dreadnought, from the Orne bridgehead by the British VIII Corps (Lieutenant-General Richard O'Connor), outflanking Caen from the east. Dreadnought was cancelled following objections from O'Connor after studying the ground and an attack towards Évrecy was considered and rejected, either by Montgomery or Dempsey. In a postwar interview with Chester Wilmot, Dempsey claimed that he told Montgomery that he was going to cancel the proposed operation on 18 June. The weather from 19 to 22 June grounded Allied aircraft and the Germans took advantage of the respite from air attacks to improve their defences. Infantry positions were protected with minefields and 88 mm guns were dug into hedgerows and woods covering the approaches to Caen.

Plan

On 20 June, Field Marshal Erwin Rommel, the commander of Heeresgruppe B (Army Group B), was ordered by Hitler to launch a counter-offensive against the Allies between the towns of Caumont-l'Éventé (Caumont) and Saint-Lô. The objective was to cut a corridor between the American and British armies, by recapturing the city of Bayeux (taken by the British on 7 June) and the coast beyond. Four SS panzer divisions and one Heer panzer division were assigned to the task. Their assault was to be spearheaded by the II SS Panzer Corps, comprising the 9th SS Panzer Division Hohenstaufen and 10th SS Panzer Division Frundsberg, recently arrived from the Eastern Front. The 1st SS Panzer Division Leibstandarte SS Adolf Hitler, 2nd SS Panzer Division Das Reich and 2nd Panzer Division would support the attack. Most of the tanks used by these formations were Panzer IVs and Panthers, supplemented by sturmgeschütz (assault guns) and Tigers—the Panthers and Tigers being among the most lethal and well-protected German armoured vehicles of the war.

On 18 June, Montgomery issued a directive to Dempsey to launch a new pincer attack with the aim of capturing Caen. The initial plan called for I and XXX Corps to attack west of Caen for four days, before VIII Corps launched the main attack out of the Orne bridgehead, east of Caen, on 22 June. It was soon realised that VIII Corps would not be able to assemble within the small perimeter of the Orne bridgehead and the following day the plan was revised. A preliminary operation was to take place three days before the main assault. The 51st (Highland) Infantry Division (I Corps) was ordered to strike south from the Orne bridgehead, to prevent units of the 21st Panzer Division from being transferred. Operation Martlet was to commence one day before Epsom with the 49th (West Riding) Infantry Division and the 8th Armoured Brigade (XXX Corps) securing the right flank of VIII Corps, by capturing the high ground to the south-west.

The main role in Operation Epsom was assigned to the newly arrived VIII Corps, consisting of 60,244 men. VIII Corps would launch their offensive from the beachhead gained by the 3rd Canadian Infantry Division. Their operation was to take place in four phases, with its ultimate objective being the high ground near Bretteville-sur-Laize, south of Caen. VIII Corps would be supported by fire from 736 guns, three cruisers and the monitor . The Royal Air Force was to provide a preliminary bombardment by 250 bombers and close air support thereafter.

The 15th (Scottish) Infantry Division would lead the assault. During Phase I, codenamed Gout, they were to take the villages of Sainte Manvieu and Cheux. In Phase II (Hangover), the division would advance to capture several crossings over the Odon River and the villages of Mouen and Grainville-sur-Odon. Should resistance during the opening phase prove light, the 11th Armoured Division would seize the bridges over the Odon River by coup de main. During the first two phases, the 43rd (Wessex) Infantry Division—to be reinforced on 28 June with the infantry brigade of the Guards Armoured Division—was to remain on the start line to provide a "firm base".

In the third phase, Impetigo, the 43rd Division would move forward to relieve all Scottish infantry north of the Odon. The 15th Division would then assemble across the river and expand the bridgehead by capturing several important villages. In the final phase, codenamed Goitre, elements of the 43rd Division would cross the river to hold the area taken, while the 15th Division would continue to expand their bridgehead. The 11th Armoured Division would attempt to force a crossing over the River Orne and advance on their final objective of Bretteville-sur-Laize. The 4th Armoured Brigade, although attached to the 11th Armoured Division, was restricted to operations between the Odon and Orne to protect the Corps flank and to be in a position to attack westwards or towards Caen, as necessary.

Depending on the success of VIII Corps attack, I Corps would then launch two supporting operations codenamed Aberlour and Ottawa. In the former the 3rd Infantry Division, supported by a Canadian infantry brigade, would attack north of Caen; the latter would be a move by the 3rd Canadian Infantry Division and the 2nd Canadian Armoured Brigade to take the village and airfield of Carpiquet. Originally planned for 22 June, Epsom was postponed until 26 June, to make up deficiencies in manpower and materiel. The initial opposition was expected to come from the depleted 12th SS Panzer Division Hitlerjugend ("Hitler Youth"), elements of the 21st Panzer Division, and the Panzer Lehr.

Operation Martlet

On 23 June, the 51st (Highland) Infantry Division attacked with the 152nd (Highland) Infantry Brigade. The Highland infantry advanced towards the village of Sainte-Honorine-la-Chardronette before daybreak, without an artillery bombardment, surprising the German garrison. The Highlanders were counter-attacked by Kampfgruppe von Luck of the 21st Panzer Division during the morning but by midday the village was firmly in British hands. German attention and resources were diverted by the success of the Highlanders as VIII Corps prepared for further attacks out of the Orne bridgehead.

At 0415 on 25 June, the 49th (West Riding) Infantry Division supported by the 8th Armoured Brigade and 250 guns, began Operation Martlet against the junction of the Panzer Lehr and 12th SS Panzer divisions. The first objective, Fontenay-le-Pesnel was fought over all day but stubborn German resistance prevented its capture. An infantry battalion supported by tanks, advanced around the village to the west and took Tessel Wood, where they received several German counter-attacks, which were repulsed by British artillery fire and close air support. By nightfall, the 49th Division had failed to reach Rauray leaving the terrain dominating the right flank of VIII Corps in German hands. Martlet forced the I SS Panzer Corps to commit the remaining tanks of the 12th SS Panzer Division against the XXX Corps front, for a counter-attack the following day. During the night, the Germans in Fontenay-le-Pesnel withdrew to straighten the front line and infantry from the 49th Division secured the village before dawn.

Battle

26 June

Poor weather hampered the start of Operation Epsom on 26 June, where rain over the battlefield had made the ground boggy; over the United Kingdom in the early hours, there was a heavy mist resulting in aircraft being grounded and the bombing being called off. No. 83 Group RAF, based in Normandy, were able to provide air support throughout the operation.