Robert Hooper Downing was one of two children born to Robert James Downing and his wife, Mary Ellen, nee Scown. BY 1914, Mary Ellen was a widow, living with her two sons at 10 Grey Street, East Melbourne. Her elder son, , Robert Clifford Downing, born 1889, enlisted for the war on 29 October, 1917. By then Robert Downing had been serving in France for over a year. He had enlisted on 19 January, 1916, and was sent for training with the Australian Army Service Corps at Broadmeadows. From Broadmeadows, he left for overseas service on 7 September, 1916, on board HMAT Port Sydney A15,  arrivng in Plymouth on 29 October. 

In civilian life, he had been a clerk and grocer, and was a fit  stone 13 stone in weight and 6 feet tall. He was first sent to Parkhouse, to the Australian Supply Corps Training Depot, where he was transferred from transport to supply. Originally destined to be a driver with the 2nd Division DVS, he moved to the Australian Army Service Corps, and served in a supply capacity for the whole war. He was taken on strength in France on 17 January, 1917, and finally dismissed from further service on 19 May, 1919. By then he had been promoted to Temporary Corporal, but this seems never to have been made permanent. There is little information in his army record. he was ill on various occasions and finally diagnosed with flat feet in 1918, but generally, he came through unscathed. He was even able to travel on leave in the last years of the war: on 25/8/1917, to the United Kingdom; on 22/12/1917, to Paris; on 17/8/1918, to Nice; on 9/11/1918, to England.

On 19 May, 1919, he was sent back to England and marched out to Sutton Veny where he stayed until  1 July, when he boarded the SS Frankfurt for the return to Australia. he was discharged from further service on 4 October, 1919.

Robert Hooper Downing never married. He came back to his mother's home immediately follwing the war, living with her at 128 Albert St., East Melbourne, and working as a clerk. By 1924, he was living at 238 Lennox St., Richmond, a clerk. The last entry for him on the Electoral Roll is in 1931, when he was working as a hotle-keeper, at 545 Chruch St., Richmond. He died, aged 42,  in Richmond, Victoria.