[1] He served on both the Western and Italian Fronts with the 1st Battalion of his regiment, a Regular Army unit that was part of the 95th Brigade of the 5th Division.

In 1919 Evelegh served with the Allied Relief Mission to North Russia during the Russian Civil War, where he was wounded.

He saw active service during the Battle of France as part of the British Expeditionary Force (BEF), serving on the staff of II Corps, then commanded by Lieutenant General Sir Alan Brooke, and being made an Officer of the Order of the British Empire, for "distinguished services in the field", on 11 July 1940.

[14][19] Evelegh commanded the 78th Division in North Africa as part of Lieutenant General Charles Allfrey's V Corps, itself part of Lieutenant General Kenneth Anderson's British First Army, seeing action throughout the Tunisian campaign, from November 1942 until the campaign's successful conclusion in mid-May 1943.

[21] On 5 August he was made a Companion of the Order of the Bath "in recognition of gallant and distinguished services in Tunisia" and soon after was granted permission to wear the insignia of a Commander of the Legion of Merit, which had been conferred on him by the United States.