William entered the war in the Balkans on 26th September 1915. On 6th November 1915, the Highland Mounted Brigade Field Ambulance's commanding officer, Lieutenant Colonel J W Mackenzie, wrote in the unit war diary: “About 12:00 o’clock a British aeroplane fell into the sea near the 14th Casualty Clearing Station, about 50 yards from the shore. The Turks opened fire on it with shrapnel & percussion shell. As our Hospital was in the line of fire & shells dropping short landed in our Camp area, one shrapnel shell entered a hospital bell tent, struck No.1414 Pte. W.V.H. Elder of my Unit on the skull, fracturing it badly, at 1300. I rendered 1st aid & removed him to the Scottish Horse F.A., where Captain Wade operated on him but he died at 1900 o’clock & was buried that night. Pte. Elder was one of my best nursing orderlies & was a keen active lad, an excellent signaler & had a clean crime sheet. The shell exploded in the sand between the legs of Driver T. Fraser, H.M.B.F.A. and a patient in the tent with his hair singed.” William was the son of Horatio and Ada Laura Elder of 14 White Rock Place, Southwick, Sussex