The 3rd (The King's Own) Hussars was a cavalry regiment of the British Army, first raised in 1685. It saw service for three centuries, including the First World War and the Second World War, before being amalgamated with the 7th Queen's Own Hussars, to form the Queen's Own Hussars in November 1958. From Wikipedia with thanks.
The Commonwealth War Graves Commission has 125 recorded WW1 deaths for the 3rd (King's Own) Hussars.
BLANDFORD, W.F. Lance Corporal, 15379. 3rd (King's Own) Hussars. Etaples Military Cemetery, Pas-de-Calais, France. 13-07-1918. Age 24. Son of Walter & Clara Blandford of Bournemouth, Dorset, UK.
FREEMAN, Arthur Cyril Bruce. Lieutenant. 3rd (King's Own) Hussars & 2nd Battalion, Royal Scots Fusiliers. Hermies Hill British cemetery, Pas-de-Calais, France. 27-09-1918. Age 22. Son of Captain Reginald Freeman (late 3rd (King's Own) Hussars) & Mrs. E.C. Freeman of Wyndham House, Sloane Gardens, London, UK.
Joined 3rd (King's Own)Hussars from Sandhurst in 1914.