In 1865 Cavaye was commissioned as an ensign into the
107th Regiment of Foot. He rose through the officer ranks to become a
lieutenant on 9 March 1867, a
captain on 13 December 1874, and a
major on 1 July 1881, having served with distinction in the
Anglo-Zulu War of 1879. The 107th Foot became the 2nd Battalion of the
Royal Sussex Regiment under the
Childers reforms of 1881: Cavaye became the battalion's commanding officer with the rank of lieutenant-colonel on 15 August 1883. Cavaye was further promoted, becoming
Assistant Adjutant General and chief of staff of the Southern District with the rank of colonel. He served "on special service" in the
Second Boer War of 1899–1902, and was
mentioned in despatches. and retired from the army on 15 December 1902. Following the outbreak of the
First World War, Cavaye returned to active service. He was appointed commanding officer of the
2nd East Anglian Division in November 1914 with the rank of brigadier-general. The division did not serve abroad, but Cavaye subsequently served on "special service" with the
British Expeditionary Force in France from 1917 to 1919, and was raised to the rank of major-general. From 1919 to 1920 he was a
King's Messenger. ==Local government==