William Geggie was born in East Melbourne, probably in May, 1888. He does not seem to have any other connection with the suburb, but lived with his father, also William Geggie, at 4 Caroline Street, South Yarra. He enlisted on 29 December, 1915, having had three yearsa previosu military training wuth the 56th Infantry Yarra Borderers. He was a labourer by occupation, single and belonged to the Presbyterian Church.

He was sent first to military camp at Ballarat, where he was attached to the 14th Depot Battalion. From there, he was moved to Broadmeadows camp as part of the 8th Battalion, 15th Reinforcements. He embarked for Egypt on board HMAT Wiltshire A18 on 7 March, 1916, where he was taken on strength with the 60th  Battalion.

The 60th Battalion was raised on Egypt on 28 February, 1916. Helf the recruits were veterans of the Gallipoli campaign returned to Egypt in mid-December, the other half, like Bill Geggie, were new recruits from Australia. The aim was to double the existing size of the Australian contingent to fight in Europe. Unfortunately for Bill Geggie, he became ill in May at Tel-el-Kebir, though the cause is not in his record. The 60th Battalion was transferred to France, arriving at Rouen on 28 June, 1916. From here, they were sent straight to the battle front, without first experiencing lighter duties in the 'nursery sector'. 

Their first battle was at Fromelles on 19 July, 1916, where the 60th Battalion was nearly wiped out, suffering 757 casualties. After being reinforced, they fought for the next two years in France (the Somme) and Belgium (Ypres), though not in the front line. In May, 1817, they were at Bullecourt, and in September, at Plygon Wood as the Allies advanced towards the Hindenburg Line. 

William Geggie was probably at Fromelles, but on 12 September, 1916, was taken to hospital. The illness was identified as pustionlosis, a condition causing large, watery blisters to form on the palms of hands and soles of feet. he rejoined the battalion on 2 October, only to be re-admitted to hospital on 29 October. On 5 November, he was sent ot hosptial in Rouen and then transferred to England on HS Western Australian. he was placed in the Southern General Hospital, where he was diagnosed with trench fever. he was released from hospital on 28 November, and sent to Wareham for convalescence. He may have been given furlough as part of the recovery. Certainly he was still in England in late February, when he wa placed at Bulford Hospital, with V.D. Discherged on 7 March, he was finally returned to France, where he was attached to the 65th Battalion on 23 March, 1917. He fought on the Western Front for most of the remainder of the year, as the allied advance on the Hindenburg Line was being enacted. In May, he was at Bullecourt with the Fifth Division, then in late September at  Polygon Wood. 

At the end of that horrendous year, he was back in hospital, admitted first to the 5th Australian Field Ambulance on 5 December, 1917, and discharged to duty on 12 December. On 9 April, he was suffering from trench feet and admitted first to the 2/3 Field Ambulance, then to the 3rd Stationary Hospital at Rouen. on 14 May, he was at Base Depot after convalescence. He was sent back to the front wher he had an accident with a knife, lacerating his right hand. In a sense, this seems to have been a turnign point in his health. From then on, he was suffering from disability, and after the Battle of Peronne/ Mt. St Quentin from 1-3 September, 1918, from the effects of gas. On 2 September, he was with the 5th Australian Field Ambulance, transferred to the General Hospital on 7 September, then transferred again, this time to England and admitted to hospital in Exeter on 10 September.

Although he was released from hospital care on 15 October, the doctors agreed that he could no longer be part of the battle. He was discharged to furlough on 15 October and told to report back to the army authorities on 29 October to the No.4 Depot at Hurdcott. He did not complete his furlough, but was again sent to hospital, probably with influenza. Discharged again on 26 October,  he reported to the No.1 Command Depot at Sutton Veny. 

William Geggie was sent home on 15 January, 1919, embarking on the City of Exeter. He arrived in Melbourne on 2 March and was discharged from the AIF as medically unfit, suffering from 'gas and debility'. He had been judged as having one-third unfitness and needing another six months recuperation. He returned home to his parents, and in 1924, was living with them at 34 Wright St., Prahran. His father was not working, his mother worked as a laundress and he was working again as a labourer. By 1928, they had moved to Spring Rd., Dandenong, again with both mother and son working. In 1949, mother and son were still together, living at 34 Duke St., Collingwood. He was still there in 1963, but this is the last mention of him in the Electoral Rolls, and there appears to be no entry in the Death Index for him.