He won the VC on 3 July 1879 at Ulundi in South Africa during the Anglo-Zulu War when he was 28 years old, and a captain in the Frontier Light Horse.

During the Anglo-Zulu War of 1879, Cecil D'Arcy was an officer in the Frontier Light Horse, a mounted unit of 200 volunteers raised at King William's Town in 1877 by Lieutenant Frederick Carrington.

D'Arcy was recommended for the VC by Evelyn Wood for going back to save the lives of wounded men in the descent of Devil's Pass; the award was not approved on the grounds that he was a volunteer and not a member of the imperial forces.

Five other awards were approved,[1] including to Colonel Redvers Buller; he had rescued D'Arcy who was retiring on foot and carrying him on his horse, while hotly pursued by Zulus.

[9] No longer is anyone likely to imitate Captain Henry Cecil Dudgeon D'Arcy of the Frontier Light Horse, who, having been awarded the VC in the Zulu wars, turned to drink.

Only many decades later was it learnt that D'Arcy had found a dead man lying in the snow, changed clothes with him, and gone to Natal, and lived out the rest of his life under an assumed name.