Per his military service record (regimental no. 2230), Leslie Sullivan was born at Orange, N.S.W. He gave his age as 18 years, his marital status as single, and his occupation as general labourer. His description on his certificate of medical examination was height 5 feet 8 inches tall, weight 9 stone 13 lbs., with a fair complexion, blue eyes, and fair hair. His religious denomination was Roman Catholic. He claimed that he had no previous military service.
The Wellington Times named Leslie J. Sullivan as one of six recruits who ‘handed in their names’ after an address given at Bodangora by Private W. J. Johnson (who was also the Mayor of Auburn), who was accompanying the Coo-ees from Wellington to Orange to assist with the recruiting speeches.
Leslie Sullivan completed his medical examination at Wellington on 16th October 1915 (when the Coo-ees were at Wellington). His father James Sullivan gave his signature for consent to the enlistment of his son on the Application to Enlist in the Australian Imperial Force paper which was addressed to the Recruiting Officer at Dripstone, and dated 19th October 1915. He was attested at Dripstone by Captain Nicholas on the 19th October 1915.
The Wellington Times reported that Leslie Sullivan in a note home described the Coo-ee March ‘trip as splendid, and says it is worth walking over the mountains to see the wonderful sights, and that he also ‘speaks very highly of the O.C., and says there is not a man among them who would not follow him to the hottest fighting place in the Dardanelles’.
After completing the Coo-ee March he went to Liverpool Camp as reinforcement for the 6th Light Horse Regiment.
The Wellington Times reported that Leslie Sullivan was given a send-off by the people of Bodangora in the Convent School Hall on Monday 7th February 2016, with singing, dancing and recitations during the evening’s festivities, where he was presented with a wristlet watch, a pocket wallet, a safety shaving set in a silver case, and a set of military hair brushes in a leather case. He was also given a fountain pen in a silver case to give to Trooper Jimmy [James] Taylor at Liverpool Camp, who had left with him from Bodangora to join the Coo-ees. In returning thanks, Trooper Sullivan said ‘he could not speak well, but he thanked them and would do his best’.
On his embarkation roll his address at time of enrolment was Bodangora, Wellington, N.S.W., and his next of kin is listed as his mother, Mrs Alice Elizabeth Sullivan, at the same address.
On 22nd March 1916 Trooper Sullivan departed Sydney on the HMAT A4 Pera, as 15th reinforcement for the 6th Light Horse Regiment.
After arriving at Suez in Egypt, on the 21st April 1916 Trooper Sullivan was admitted to the Government Hospital sick. On 22nd April 1916 Trooper Sullivan was taken on strength of the 2nd Light Horse Training Battalion, whilst in hospital.
On 25th April 1916 he was transferred to the 1st Australian Dermatological Hospital at Abbassia, Egypt. He was discharged on 2nd June 1916 and marched into the 2nd Light Horse Training Regiment at Tel-el-Kebir, Egypt on 5th June 1916.
On 6th July 1916 Trooper Sullivan was transferred to the 2nd Double Squadron at Serapeum, Egypt.
On 2nd November 1916 he was transferred to the 4th Australian Camel Regiment at Abbassia, Egypt.
On 13th January 1917 Trooper Sullivan was charged with being absent without leave from 1800 till 2030 on 11th January 1917. He was awarded 7 days confined to barracks.
On 24th January 1917 Trooper Sullivan was charged with being absent without leave from 1700 till 2120 on the 23rd January 1917. He was awarded 14 days confined to barracks.
On 7th February 1917 Trooper Sullivan was transferred to the 17th Company of the Imperial Camel Corps.
On 10th March 1918 Trooper Sullivan was sent to the Port Said Rest Camp. He rejoined his unit on 8th April 1918.
On 28th May 1918 Trooper Sullivan was promoted to Lance Corporal.
On 29th June 1918 Lance Corporal Sullivan was admitted to the Isolation Camp sick. On 10th July 1918 he was transferred to the 26th Stationary Hospital at Ismailia, Egypt. On 1st August 1918 he was sent to the Port Said Rest Camp. He was discharged on 15th August 1918.
On 23rd August 1918 Lance Corporal Sullivan was transferred to the 14th Light Horse Regiment at Ismailia, Egypt.
On 25th October 1918 Lance Corporal Sullivan was sent to hospital sick. On 5th November 1918 he was transferred to the 31st General Hospital at Ismailia, Egypt, suffering from Influenza. He was discharged on 16th November 1918. On 20th November 1918 he was sent to the Port Said Rest Camp.
He rejoined his unit on 12th December 1918.
On 5th February 1919 Lance Corporal Sullivan was admitted to hospital suffering from Malaria. He was transferred to a Convalescent Depot on 6th March 1919.
He rejoined his unit at Moascar on 13th March 1919.
On 14th June 1919 he was charged with being absent without leave from 0630 till 0915 on 8th June 1919, and was deprived of one day’s pay.
Lance Corporal Sullivan commenced his return to Australia on H.T. Dongola from Kantara in Egypt on 24th July 1919. He disembarked at Sydney on 28th August 1919.
He was discharged on 21st October 1919.
 ‘District news. Bodangora’, Wellington Times, 21 October 1915, p. 5, http://nla.gov.au/nla.news-article143396661
 ‘District news. Bodangora’, Wellington Times, 11 November 1915 , p. 5, http://nla.gov.au/nla.news-article143396376
 ‘Send off to Trooper Leslie Sullivan’, Wellington Times, 10 February 1916 , p. 7, http://nla.gov.au/nla.news-article143392079