Sydney Hartley Graham was a married man, an accountant and aged 36 when he enlisted at Adelaide on 7 March 1917. He had married his wife, Christina Jane, nee Macrae, on 11 January, 1911. The couple had no children and were living at 6 berkshire Street, Glenelg, South Australia. He was first sent to train on 1 May, 1917, with B Company at Mitcham,  then transferred to Maribynong, Victoria where he was placed with the 32nd Field Artillery Reinforcements. After training, they embarked on SS Indarra on 12 November, 1917, disembarking at Southampton on 15 February, 1918. in the meantime, Christina also moved to Melbourne, giving her address as 66 Clarendon Street, East Melbourne.

From Southampton, the Reinforcements went on to Heytesbury, arriving on 15 February, then were sent overseas to France on 3 March, 1917. Finally, on 16 August, 1918, Sydney Graham was taken on strength with the 2nd Field Artillery Company. On 23 September, he moved on to 104 Battery from the 2nd D.A.C. to the 4th Field Artillery Brigade. As the war ended, however, he becamse more useful in adminstration than fighting and was transferred back to London to AIF Administrative Headquarters. He remained there until 15 May, 1919, when he was again detached, this time to the Australian Army Pay Corps, in the Audit Section. 

He embarked on HS Konigen Luise 21 June 1919, on the Pay Staff. he is remembered on the Memorial at UNley South Australia.