 Everard was born in Barnet and educated at Marlborough College and graduated from Trinity College, Cambridge in 1922.During the First World War he served in France with the Rifle Brigade, where he was wounded in combat and reached the rank of Captain.He worked as a railway engineer from 1922, but was commissioned again on the outbreak of the Second World War, this time in the Sherwood Foresters; he was taken prisoner by German forces, awarded the Distinguished Service Order, and reached the rank of Lieutenant-Colonel.