William George Gilbert was born in East Melbourne and on enlisting, gave his address as 115 Erskine Street, Middle Park. He have his mother, Annie Taylor as his next of kin, advising that she lived at 55 Munro Street, East Melbourne. Her address, in fact, was 56 Munro Street, West Brunswick. Ther was also confusion about his name: in the Embarkation Record and with the photograph held by the Australian War Museum, he is William George Gilbert, but the National Archives of Australia have him as William Genge Gilbert, No 3332, so finding his Service Record was difficult. In spite of this, his service record alwys refers to him as william George Gilbert. He was born in August 1891 and was just a month short of his 25th birthday when he enlisted on 6 July, 1915.

He was a single man, a tinsmith by trade and Roman Catholic by religion. He was passed by the army authorities as being in perfect health and on 12 July was sent to Flemington Camp for training. From Flemington, he went to Geelong from 15 August to 15 September and was then sent back to Melbourne, where he was at Broadmeadows Camp for two days before embarking for overseas. By this time, he was attached to the 14th Battalion. They left Australia on 11 October, 1915, on board HMAT Nestor A71 for Egypt. 

On 4 February, 1916, William Glibert was taken on strength with the 14th battalion at Moascar Camp, Ismailia. 

However, he was not long in training there: on 28 February, he was sent to the 2 Australian Stationary Hospital with mumps and on 4 March, was transferred to hospital at Tel-el-Kebir. He was discharged in early March, rejoining his unit on 17 March. However, he was not well, with chest pains at night and breathing difficulties on drill. He was transferred ot the 4th Training Battalion on 19 March, but on 3 June, was re-admitted to hospital. His condition was serious enough for him to be returned to Australia.

A report written on 3 March, 1916, reported: N0 history of  of any previous illness. Arrived in Egypt Nov. 1915. Was in good health till after March 27 1916 then found he was gradually getting shortness of breath and will not drill. Admitted to No. 3 Australian General Hospital with Dilated Heart.A

A later report atached to his application for a pension said  ...  Private William George Gilbert 14th  Battalion was admitted on 4th June 1916 to the 3rd Australian General Hospital Cairo; was invalided to Australia and returned via "Port Sydney" which reached Melbourne on 22nd July, 1916, illness being reported as dilated heart; was diagnosed as medically unfit on 31st August 1916.

William Gilbert returned to live with his mother, Annie,  and brother Thomas in West Brunswick and was awarded a pension of three pounds per fortnight from 1 September 1916, reduced to two pounds a year later. Annie was given a pension of one pound per fortnight. In 1935, he wrote to the Department of Repatriation from 16 Collier Street, West Brunswick.

He cannot be found in the Electoral Roll beyond 1925, when he was living at 35 Collier Crescent West Brunswick.