Vico family, the owner of the Western part of the Abbey, was actively involved in Resistance activities: intelligence, training sessions, hiding parachuted weapons, etc. On 6th June 1944, the Allied forces landed on the beaches of Normandy. The Abbey represented a strategic asset and was taken over by the 12th SS Panzer Division Hitlerjugend. Perched on the towers of the abbey, German soldiers watched every movement of the Allied Forces, from the landing beaches to Falaise, located inland. Fierce fighting, mainly artillery fire, went on for a month.
On 7th June 1944, at the opening of the battle, German soldiers captured Canadian soldiers and led them to the Abbey. Eighteen of them were executed, in violation of the Geneva Convention on the treatment of prisoners of war. Other summary executions were also carried out during this month of fighting. A war memorial commemorates this tragic event in Ardenne Abbey.
The abbey was taken back from the Germans on 8th July 1944 by the Canadian soldiers of the Regina Rifle Regiment, which enabled the liberation of the left bank of Caen the following day.
The constant fighting in Caen and its area took its toll on the population during this month. 70% of the city of Caen was destroyed. Ardenne Abbey was reduced to ruins. All the roofs of the farm buildings were blown away, the framework was burnt, and the walls were torn open. The Tithe Barn, where the armoured vehicles had been sheltered, was almost razed. The abbey remained standing, but was extremely damaged.