When he enlisted at Melbourne on 22 August 1914 Ernest St Clair stated that he was 22 years and 8 months old and that he was born in Melbourne.  However this cannot be confirmed in the official records.  He gave his address as 141 Napier Street, Fitzroy. His occupation was motor mechanic and he stated that he had been apprenticed to the Motor House Coy, St. Kilda Road.  He gave as his next of kin his brother, Ronald St Clair, who had enlisted five days’ earlier, and was a member of E Company, 6th Battalion.  Ronald declared himself to be 22 years and 3 months. Ernest had been for 18 months a member of A Company, 6th AIR (Australian Infantry Regiment).  He was appointed to E Company, 6th Battalion, his brother’s unit.
He embarked, with his brother, on 19 October 1914 aboard HMAT Hororata.  The embarkation roll gave his address as 21 [now 574, demolished] Victoria Parade, East Melbourne.  Ronald had given Ernest as his next of kin and, curiously, gave his address as 1 Napier Street, Fitzroy, which was also his own address. Ernest was wounded at Anzac on 11 July 1915 and evacuated to Malta a week later, suffering shock and deafness.  On 9 September 1915 he embarked for Australia from Suez for discharge.  He arrived home 4 October 1915 and was discharged on 24 January 1916.
A memo from Base Records 9 December 1915 shows that Ernest had changed his next of kin to his friend, Miss Coral Pullar of 21 Victoria Parade, who had ‘evidently been drawing an allotment of 4/- per day although it is not shown on the nominal roll in this office.’ Ernest married Coral in 1917. By 1925 Ernest, then on 47 Edgar Street, East Malvern, was in serious financial difficulty with the sheriff due to sell his block of land in Malvern; whether this was his house or another block is unclear. He wrote from 77 Paxton Street, East Malvern on 2 August 1964 requesting his Anzac Commemorative Medallion.