William Cotterill is a slippery character and his relationship to East Melbourne is tenuous. He first enlisted for the First World War at Liverpool NSW on 25 November, 1915. He was then 42 years' old and was dscribed as 5'6" tall with tattoos on both forearms and chest. He stated that he was born in Manchester, England and had already had twelve years military service in the Manchester Regiment. He was married, but separated from his wife and named as his next of kin his friend, Mrs. Short, living at 1 Altona St., Pyrmont, NSW. He was a miner by occulation and  gave his permanent address as Scott's Hotel, Melbourne Street, Hobart. He was sent to Claremont, where he was placed in the 1st Depot Battalion on the day he enlisted. Seven weeks later, he overstayed his leave and on his return was transferred from the 19th battalion to the 7/4 battalion. On 24 May, he was due to embark on HMAT Suffolk A23, but failed to turn up.

He enlisted again on 14 January, 1916, in Hobart and was transferred to Melbourne, where he was placed in the 13th Australian Army Motor Corps. but deserted on 13 June, 1916. He enlisted for the third time on 9 January, 1918, this time in Melbourne, and was taken into the 2nd Depot Battalion at Broadmeadows.  On his enlisment form, he declared that he had been born in Hobart, Tasmania, was a labourer and married to Kate Ellen Cotterill of 514 Albert Street, East melbourne. Following training, he was placed in the 10th Reinforcements for the 46th Battalion. They embarked from Melbourne on 13 March, 1918 on board on HMAT Nestor A71. On reaching England, William Cotterill again deserted, going absent without leave on 15 May. he was arrested by the military police on 18 May, fined and given field duty, but again absconded from Codford camp on 16 June and  was not arrested until 31 July, for which offence he forfeited 45 days's pay. This was not the end of his misdemeanors, going AWL from 11-30 August. 

William Cotterill was finally sent to France, sailing from Folkestone on 6  September, 1918, and was taken on strength with the 46th battalion. By December, he was back in England, where he committed an unspecified offence in Bristol on 28 December. Following this, he again went AWL, this time from  17 January to 18 September, 1919. He was apprehended at Cardiff and, on 22 September, charged with being absent from duty for 139 days and under charge for 15 days, making in total an absence of 154 days.  An additional charge was that he was using false identity papers. he faced a District Court Martial on 7 October.

In his defence he stated that he suffered badly from rheumatism, but declined a medical examination. In his statement he said 'The reason for me hanging on in Bristol was this. My people at home were very urgently in need of ,money and I determined if possible to help. I might also state that I served 12 years with the Manchester Regiment, and thrugh the Boer War, and received both Queen's Medals with five clasps.' He further explained that he only had the identity papers because a soldier had left them behind in an hotel and the proprietor had passed them into his safekeeping. 

William Cotterill was found guilty of desertion, but not of the second charge, presenting false papaers. he served a further term of imprisonment, but was then returned to Melbourne on board HT Macumba, serving as a fireman for the duration of the voyage. He was discharged from further service on 2 May, 1920. His record was stamped 'Not Eligible' for the three service medals.