Arthur Firth was 22 years old and a tailor by trade when he enlisted on 24 December 1915. He had already served a five year apprenticeship with tailors R.T. Lloyd of Bourke St. Melbourne and had two and a half years' training in the 64th Infantry of the citizens' forces. He lived with his parents, Sydney Silver Frith, at 539 Victoria Parade, East Melbourne. Sydney Frith was a carpenter, while his wife, Nora, nee Murray, was a lodging house keeper. Arthur Frith/Firth was the fifth of five children, with an eldest sister, Florence (1881-1969) and brothers Herbert ( 1884-1934), Percy (1886-1969), and Leonard (1889-1956). 

Arthur Firth was called up on 29 March, 1915, and went into training at Broadmeadows, where he was attached to the newly-created 23rd Battalion AIF. He embarked with the other recruits to the 23rd Battalion on board HMAT Euripides A14 to Egypt. They were sent first to Egypt and then to Gallipoli, where they alternated with the 24th Battalion at Lone Pine. The 23rd Battalion evacuated their positions at Gallipoli along with the other Australian troops in December, 1915, and returned to Egypt. From here, they moved to France on 10 April, 1916, but Arthur Field was not with them. He had developed a case of piles and had been sent to hospital at Ismailia on 8 April and was not released until after the Battalion has sailed. He was therefore taken on strength with the 8th Field Company Engineers, where he worked with AIF Canteens at Ferry Post on the Suez Canal. 

From Egypt, the 8th Field Company Engineers left for France. On 15-16 June, 1916, they were in Moascar packing up, then went by train to Alexandria on 17 June, embarking the same day on HMTS Manitou. They arrived at Marseilles on 25 June, then again by train, moved to Abbeville. From here the 8th Brigade were exposed to the full brunt of the war and it may be that it was at this stage that Arthur Firth became a sapper. The Field Diary from the 8th Field Company Engineers tells the story: 29 June Arrived at Steenbecque and marched to camp at Morbecque; 30 June Company on route - marching; 1 July: Move to billet in Morbecque; 2 July Route marching in a.m.; 3 July Gas demonstration; July 4 Route marching in a.m. Moved by motor to Bac St. Muir; July 5 Gas helmet practice and inspection of equipment and clothing; 6 July Taking over work in front line from 2nd Field Coy. Enginees. Moved to Fleurbaix, into old school. They were preparing for the battle of Fromelles: by 11 July, they were consrtucting earthworks, with the 8th Brigade 'holding line'. On 16 July, thye set up stores, presumably of ammunition, and were improving communication as 'attack the next day ... moved into assault position.'It is unclear when Arthur Firth left his comapany, but on 20 July, 1916, he was back in England, having been admitted to the 1st Australian Dermatological Hospital at Bulford with VD. The hospital specialised in venereal disease and Arthur Firth remained there for 56 days under treatment. After a further period of recuperation and training at Perham Downs, he was back in France, taken on strength with teh 8th Field Company Engineers on 20 February, 1917. 

On 2 June, 1917, he was discharged to duty, but on 27 August, he was accidentally injured, with a simple fracture to the left radius and admitted to the 53rd Casualty Clearing Station at Rouen. As he testified to the Medical Inquiry into his injury I was carrying a box to be loaded on the transport. I slipped and fell, breaking my arm.

He further testified that the ground was very uneven and this was the cause of the accident. He was transferred to the Kitchener Military Hospital at Brighton on 30 August, 1917, then on to the 3rd Auxiliary Hospital at Dartford on 17 September. With the arm mended, he was granted furlough on 19 October and ordered to report to the No. 1 Command Depot at Hurdcott. He returned to duty on 10 December, 1918, but with the war over, he left England for home on HT Berrima  on 2 January, 1919. He disembarked in Melbourne on 17 February, 1919, ad was discharged from the army on 11 April, 1919.

No trace of Arthur Firth in the post-war years can be found in Electoral Rolls. IN fact, he immediately returned to being Arthur Frith and in 1919 was living with his parents again at 539 Victoria Parade, East Melbourne. In 1944, he married Louisa Tevelich (1899-1986)  They lived at 34 Merton Street, Albert Park. He died in 1952, still at Albert Park.