[3] However, Charles was unable to travel from his home at Down House in Kent to Cambridge to see his newborn grandson due to his ill health;[2] his heart was failing and would eventually result in his death in April 1882.

[9] Darwin was commissioned as a Second Lieutenant in the 4th Battalion of the Green Howards (Alexandra Princess of Wales's Own Yorkshire Regiment), a Territorial Army infantry unit, in September 1914,[11] shortly after the outbreak of the war in August.

The Green Howards joined the British Expeditionary Force in Belgium and France on the Western Front as part of the Northumbrian Division, on 17 April 1915.

He, along with a close colleague Captain John Nancarrow[10] were reportedly "buried in one grave, with a little cross over it, by a farmhouse near St Julien.

[9] Darwin family letters noted: "The Royal Irish Fusiliers recovered his body along with that of Captain Nancarrow and the two were buried together with a little cross over it by a farmhouse near St Julien."

Commanding Officer, Colonel Bell wrote of him:- "Loyalty, courage and devotion to duty, he had them all.....He died in an attack which gained many compliments to the Battn.

A separate memorial book by Bernard, Erasmus Darwin: Born 7 December 1881, Killed in Action 24 April 1915 was also published.

His name appears on the Saltburn by the Sea war memorial, which stands close to his last home in Albion Terrace, as listed in the 1911 census.