Roy Precious - Antiques & Fine Art has dated this piece to the 1910s.

The sitter wears the red hatband and tabs of an officer of the General Staff but, to judge by his decorations he had seen action, as amongst their number is the D.S.O.
(The Distinguished Service Order was awarded for meritorious or distinguished service by officers of the armed forces during wartime, usually in actual combat. It is typically awarded to officers ranked Major (or its equivalent) or higher, but the honour has sometimes been awarded to especially valorous junior officers. 8,981 DSOs were awarded during the First World War, each award being announced in the London Gazette.)

The identity of the young officer is unknown as is whether he survived the Great War.
LEON SPRINCK was a fashionable artist of Russian stock, he painted many aristocrats and members of the gentry. In the late 19th and early 20th centuries he exhibited at the Royal Academy, London, the Royal Hibernian Academy and the Walker Art Gallery, Liverpool. He lived at Portland Place in London.
SIZE: 39 x 34 inches inc. frame.
PROVENANCE: Collection of a retired army officer, Westmoreland country house.
Verso; old storage label " A & N.C.S.L. No.25. Mrs. Wickham April 1972".
Roy Precious - Antiques & Fine Art has dated this piece to the 1910s.
Roy and nadine precious: specialists in portraiture from the 16th to the 20th century. Established in 1972.
You can view the stock and full dealer information on the Roy Precious - Antiques & Fine Art Profile Page