William McGrath enlisted as a Trooper in the 8th Light Horse in 1915. He rose to the rank of Squadron Sergeant Major and was commissioned as a Second Lieutenant on Gallipoli. McGrath served throughout the war with 8th Light Horse Regiment progressing through the officer ranks. As adjutant, he compiled a history of the regiment both from personal knowledge and the regiment's war diary. McGrath's successor as adjutant, Captain Austin, is believed to have had input into the document and for some years was thought to have been the originator.
The 8th Light Horse Regiment AIF was raised at Broadmeadows Victoria in September 1914 under the command of Lieutenant Colonel Alexander White and formed part of the 3rd Light Horse Brigade. The regiment served at Gallipoli where in a courageous but ill-fated charge at the Nek on 7 August 1915 it suffered horrendous casualties including Lieutenant Colonel White. Rebuilt in Egypt under the command of Lieutenant Colonel Leslie Maygar VC the regiment went on the serve throughout the Middle East Campaign. Colonel Maygar died of wounds at Beersheba when the regiment was attacked by enemy aircraft while waiting to follow up the successful charge of the 4th LH Brigade on 30 October 1917. The 8th Light Horse AIF was disbanded in 1919, but soon after re-raised as the 8th (Indi) Light Horse in the Citizen Military Forces, superseding 16th (Indi) Light Horse
Black and white photograph of two 8th Light Horse officers ; Captains McGrath (left) and Austin. Photograph is glued to fluted plastic board.