John Fortescue Grantley Fitzhardinge was born in the inner Sydney suburb of Balmain, New South Wales, in 1886 the son of highly respected News South Wales Supreme Court Judge Grantley Hyde Fitzhardinge and his wife Julia [Yeomans], the younger brother of Grantley Hyde, Una and Julie Grantley Fitzhardinge born between 1876 and 1884, older brother of Richard born in 1888, as well as another sibling, unfortunately stillborn, in 1882.

A privileged upbringing saw the young Fitzhardinge receive his early eduction at the prestigious Sydney Church of England Grammar School [Shore] in Sydney's North Shore and subsequently St Andrews College after which he went on to study Medicine at the University of Sydney's Medical School graduating as a doctor in 1909. …show more content…
With Clara appointed as resident medical officer at the Brisbane General Hospital John also moved to Brisbane and in December 1913 they were married at the Toowong Presbyterian Church in Brisbane and they both continued to practice medicine and began a practice in Pambula on the New South Wales South Coast. Together they were appointed 'local medical officers' for the region when the second Pambula Hospital opened.

While in Pambula John and Clara welcomed their first child, Una Clara, in 1914, and over their subsequent years together they would have a further five children, Ruth, Arthur Noel, Julie Maude, Grantely William and Patricia Bleakley.

With the War effort in desperate need of medics Captain Fitzhardinge enlisted on 1 April 1916 at 30 years of age and was assigned to the Australian Army Medical Corps, 5th Light Horse and embarked from Sydney, New South Wales, on board RMS Malwa on 22 July