John Simpson Kirkpatrick was born in Britain but later moved to Australia. In August 1914 he enlisted in the Australian Imperial Force, serving at Gallipoli the following year as Private John Simpson in the 3rd Field Ambulance, Australian Army Medical Corps. He served from the time of the landing at Gallipoli on 25 April until he was killed in action on 19 May.
Simpson became famous for his work as a stretcher-bearer. Using one of the donkeys brought in for carrying water, he transported wounded men day and night from the fighting in Monash Valley to the beach on Anzac Cove. He did so, according to Charles Bean, through "deadly sniping down the valley and the most furious shrapnel fire". He was killed by machine-gun fire while carrying two wounded men and was buried on the beach at Hell Spit.
The war diary of the 3rd Field Ambulance commended "the excellence of the work performed by Pte Simpson continuously since landing". Simpson was posthumously Mentioned in Despatches. His first donkey was known as Abdul, Murphy, or Duffy.