Operation Cobra - Background

Background

Further information: Invasion of Normandy and Operation Overlord

Following the successful Allied Invasion of Normandy on 6 June 1944, progress inland was slow. To facilitate the Allied build-up in France and to secure room for further expansion, the deep water port of Cherbourg on the western flank of the American sector and the historic town of Caen in the British and Canadian sector to the east represented early objectives. The original plan for the Normandy campaign envisioned strong offensive efforts in both sectors, in which Lieutenant-General Sir Miles Dempsey's British Second Army would secure Caen and the area south of it, and Lieutenant General Omar Bradley's U.S. First Army would "wheel round" to the Loire.

General Bernard Montgomery—commanding all Allied ground forces in Normandy—intended Caen to be taken on D-Day, while Cherbourg was expected to fall 15 days later. Second Army was to seize Caen and then form a front to the south-east, extending to Caumont-l'Éventé, to acquire airfields and protect First Army's left flank while it moved on Cherbourg. Possession of Caen and its surroundings—desirable for open terrain that would permit maneuver warfare—would also give Second Army a suitable staging area for a push south to capture Falaise, which could be used as the pivot for a swing right to advance on Argentan and then towards the Touques River. Caen's capture has been described by historian L. F. Ellis as the most important D-Day objective assigned to Lieutenant-General Crockers's I Corps. However, both Ellis and Chester Wilmot characterize the Allied plan as "ambitious"; the Caen sector contained the strongest defences in Normandy.

The initial attempt by I Corps to reach the city on D-Day was blocked by elements of the 21st Panzer Division, and with the Germans committing to the city's defense most of the reinforcements sent to meet the invasion, the Anglo-Canadian front rapidly congealed short of Second Army's objectives. Operation Perch in the week following D-Day, and Operation Epsom (26–30 June) brought some territorial gains and depleted its defenders, but Caen remained in German hands until Operation Charnwood (7–9 July), when the Second Army managed to take the northern part of the city up to the River Orne in a frontal assault.

The successive Anglo-Canadian offensives around Caen were drawing the best of the German forces in Normandy, including most of the available armor, to the eastern end of the Allied lodgement. Even so, the U.S. First Army was struggling to make progress against dogged German resistance. In part, operations were slow due to the constraints of the bocage landscape of densely-packed banked hedgerows, sunken lanes, and small woods, for which U.S. units had not trained. Furthermore, with no port facilities in Allied hands, all reinforcement and resupply had to take place over the beaches via the two Mulberry harbors and was at the mercy of the weather. On 19 June, a severe storm descended on the English Channel, lasting for three days and causing significant delays to the Allied build-up and the cancellation of some planned operations. First Army's attempt to press forward in the western sector was eventually halted by Bradley before the town of Saint-Lô, in order to prioritize operations directed at the seizure of Cherbourg. Cherbourg's defenders were not set up for robust performance, consisting largely of four battlegroups formed from the remnants of units that had retreated up the Cotentin peninsula; the port's defences had been designed principally to meet an attack from the sea. However, organized German resistance ended only on 27 June, when the 9th Infantry Division managed to reduce the defences of Cap-de-la-Hague northwest of the city. Within four days, Major General J. Lawton "Lightning Joe" Collins's VII Corps resumed the offensive toward Saint-Lô, alongside XIX Corps and VIII Corps, causing the Germans to move additional armor into the U.S. sector.