Operation Chastity

Operation Chastity
Part of Operation Overlord on the Western Front during the Second World War
Date 3 August – 7 September, 1944 Location Quiberon Bay France 47°35′N 2°56′W / 47.583°N 2.933°W / 47.583; -2.933 Result See Debate Territorial changes Allies liberate Brittany with the exception of Brest, Lorient and Quiberon Peninsular.
Belligerents
United States	Germany
Commanders and leaders
Omar Bradley George S. Patton Troy H. Middleton John Shirley Wood	Günther von Kluge Paul Hausser Wilhelm Fahrmbacher
Units involved
Twelfth United States Army Group US Third Army US VIII Corps US 4th Armored Division	Army Group B Seventh Army XXV Army Corps

Operation Chastity was a World War II plan by the Allies to seize Quiberon Bay, France, enabling the construction of an artificial harbor to support Allied operations in Northern France in 1944.

The artificial harbor was not developed, as the US VIII Corps failed to capture German-held areas that threatened the port. By the end of August 1944, Allied forces had captured all of Brittany except for the critical areas, preventing the further development of the operation. Following the capture of Antwerp and its port facilities in early September 1944, Operation Chastity was officially cancelled on 7 September.

The non-completion and eventual cancellation of Operation Chastity exacerbated strains on the Allied logistical system, may have prevented an Allied victory over Germany in 1944, and has been described as "the critical error of World War II", although other historians believe that priority was rightly given to the pursuit of the routing German forces.