[4] Upon the completion of his degree, he entered the armed services, participating in World War I[3] as a major in the Westmorland and Cumberland Yeomanry[2] in which he was awarded the Military Cross[2] and wounded in action twice.

[1] The citation for his MC, which appeared in The London Gazette in July 1918, reads as follows: For conspicuous gallantry and devotion to duty.

He remained behind until all his men were clear, and assisted in giving covering fire with the last platoon, although badly wounded.

Henry Cecil Vane, heir apparent to the barony of Barnard, also served in the Great War[3] but was subsequently wounded and died of those wounds shortly thereafter in 1917,[6] leaving his younger brother heir apparent to the title of Baron Barnard.

In 1930 he was invested as a Commander of the Order of St. Michael and St. George,[2] and gained the honorary rank of Colonel in the service of the 6th Battalion of the Durham Light Infantry, his former unit.