Schlacht um Caen
On 6 June 1944 Mayhew commanded a company equipped with 13 armoured infantry carriers that landed at Sword Beach in Normandy, on D-Day. His unit captured the Hillman Battery, a 12-bunker complex defended by 150 men of the 736 Infantry Regiment, as part of the liberation of Colleville-sur-Orne. They then fought during the Battle for Caen, and on 28 June were part of Operation Charnwood, fighting a battle at "Château de la Londe", which left 161 dead on the British side. His company liberated Flers and moved on towards Belgium and the Netherlands.