Many volunteers from the Defence Force traveled to England and joined the British Army, and many of them were killed in action.

One of them mentioned by Arthur Conan Doyle was Private Jacotine of the Ceylon Light Infantry, who was the last man left alive in his unit at the Battle of Lys, and who continued to fight for 20 minutes before he was killed.

The CPRC performed operational duties as guards to ANZAC headquarter staff, including the General Officer Commanding ANZAC, Lieutenant General William Birdwood, who remarked, “I have an excellent guard of Ceylon Planters who are such a nice lot of fellows.” According to its onetime Commanding Officer (CO), Colonel T.Y.

Wright (1904–1912), the Ceylon Planters Rifle Corps had sustained overall losses of 80 killed and 99 wounded in the Great War.

South East Asia Command under Admiral Lord Louis Mountbatten had its headquarters located at Kandy, Ceylon.

In 1947 the CDF was again mobilised in its last major internal security operation to suppress a left wing hartal, or mass stoppage of work.

The Ceylon Defence Force was given additional support by an armed detachment of British Royal Marines from HMS Glasgow, who were utilised to deter strikers in Colombo.

The last Ceylon Defence Force veteran to leave the Army was Brigadier T. S. B. Sally, who ended his service tenure in 1979.

Much of the officer carder was made up of Europeans, Burghers and a smaller extent from the Sinhalese, Tamils and Moor communities.

A few Europeans had served with the British Army, vast majority were planters, landowners and professionals such as lawyers, doctors engineers and civil servants.