[1] Sir Delaval was a Lieutenant-Colonel in the 13th/18th Regiment of the Royal Hussars and fought in the Second World War, where he was awarded the Distinguished Service Order.

In 1942 it became clear that the Second Front would involve the 13th/18th Hussars and thus in 1944, with everything ready, the Regiment landed on D-Day with Sir Delaval in command of 'C' Squadron.

[5][6] It was said that it was vital that the village of La Variniere, on the Regiment's line of communication, should be held otherwise withdrawal from Mont Pinçon would have been inevitable.

There the armoured cars of the calvalry regiments played an important role in escorting convoys of troops and supplies and in making sure roads stayed open throughout the Emergency.

[9] During the 1960s and 1970s Sir Delaval and Lady Cotter moved back to Ireland, and bought and restored Castle Widenham in Castletownroche.