Major James Albert Edward Hamilton, third Duke of Abercorn
Hamilton was a British peer and Unionist politician. He was the first Governor of Northern Ireland, a post he held between 1922 and 1945.
Born on 30 November 1869 at Hamilton Place, Piccadilly, London, Hamilton was the eldest son of James Hamilton, 2nd Duke of Abercorn, and godson of the Prince of Wales. His mother Lady Mary Anna was the fourth daughter of Richard Curzon-Howe, 1st Earl Howe. He was educated at Eton and subsequently served in the Royal Inniskilling Fusiliers and as a captain in the Life Guards.
He joined the North of Ireland Imperial Yeomanry soon after its formation in 1902, serving as a major and second-in-command (his father was Hon. Colonel of the regiment). When the North Irish Horse was formed in July 1908 he transferred to the new regiment, but retired after a couple of years.
Hamilton became the third Duke of Abercorn on the death of his father in 1913.
He returned to the North Irish Horse on 15 August 1914 with the rank of Major (retired). In the following year he transferred to the reserve regiment of the 1st Life Guards, serving as a captain.
His overseas service during the war was brief - just over a fortnight in France conducting a fresh draft of troops there.
He died 12 September 1953.
In the image above Hamilton is wearing the uniform of a captain in the Life Guards.
I am grateful to the National Portrait Gallery for permission to reproduce this image (details below):
James Albert Edward Hamilton, 3rd Duke of Abercorn, by Henry Walter ('H. Walter') Barnett. vintage bromide print, 1914-1918, 8 3/8" x 6 1/4" (212 mm x 160 mm). Purchased, 1994. Photographs Collection NPG x45393.
Some of the above information sourced from Wikipedia.