The 15th Battalion was an infantry battalion of the Australian Army. Formed in 1914 as part of the all-volunteer Australian Imperial Force from Queensland and Tasmanian recruits, the battalion fought during the Gallipoli Campaign and on the Western Front during the First World War. It was disbanded after the war in 1919, but later re-raised as a part-time Citizens Forces unit based in Queensland in 1921, consisting of a mixture of volunteers and conscripts. Economic pressures and limited manpower resulted in the battalion being amalgamated with other battalions a couple of times during the inter-war years. In mid-1939, as rising tensions in Europe led to an expansion of the Australian military, the battalion was re-formed in its own right. During the Second World War the 15th Battalion was mobilised for wartime service and initially undertook defensive duties in Australia before taking part in the fighting against the Japanese in New Guinea and Bougainville in 1943–1945. The battalion was disbanded in 1946 and never re-raised.

History

First World War

Formation and service at Gallipoli The 15th Battalion was originally raised as part of the all-volunteer Australian Imperial Force (AIF) in September 1914. Drawing personnel from volunteers from Queensland and Tasmania, it formed part of the 4th Brigade, along with the 13th, 14th, and 16th Battalions. With an authorised strength of 1,023 men, the battalion initially consisted of eight companies, of which six came from Queensland and two from Tasmania. The Queensland companies concentrated at Enoggera in September and began initial training, while the Tasmanians formed at Claremont in October. In late November, the battalion concentrated at Broadmeadows, Victoria, under the command of Lieutenant Colonel James Cannan, who later rose to become Quartermaster General during World War II. Many of the battalion's officers and non-commissioned officers had previously served in the Citizens Forces and a few had fought in South Africa during the Boer War or in India with the British Army. Following a short period of training, the battalion embarked for overseas on the transport ship SS Ceramic in late December 1914, after marching through the streets of Melbourne. Initially it had been planned to send the Australians to fight against the Germans on the Western Front, but as a result of overcrowding and poor conditions in t training camps in the United Kingdom, it was decided that the first Australian contingent, the 1st Division, would be sent to Egypt instead.

Travelling via Albany, Western Australia, disembarked at Alexandria on 3 February 1915 and moved into camp at Heliopolis, It briefly undertook defensive duties around Kantara, when Ottoman forces raided the Suez Canal.

At Heliopolis, the battalion was assigned to Major General Alexander Godley's New Zealand and Australian Division. Upon arrival, the battalion was reorganised by merging the eight companies into four larger companies, designated 'A' through to 'D'. Shortly afterwards, the battalion's first draft of reinforcements arrived and an extensive period of training in the desert followed throughout February and March. Finally, on 10 April, the 15th Battalion was moved by train to Alexandria, where it embarked upon the troopships Seeang Bee and Australind, bound for Gallipoli. After leaving Alexandria, the 15th Battalion sailed to Mudros, where the Allied force assembled prior to the assault. Assigned to the follow-up waves, the 15th Battalion landed at Anzac Cove on the afternoon of 25 April 1915. As the Ottoman defenders checked the Allied advance inland, on arrival the 15th Battalion was rushed into the line on the left flank of the beachhead. As the advance inland stalled, the battalion became isolated and threatened with destruction until Cannan withdrew his force to a more tenable position. Later, they helped shore up the line before occupying positions around "Pope's Hill" and "Russell's Top", where they joined an attack on 1 May. After that, they occupied "Quinn's Post", and defended it against a strong Ottoman counterattack on 19 May. Further fighting occurred around the battalion's position as the Ottoman troops began tunnelling under the "no man's land" that divided the two lines. Counter-mining actions were undertaken, but on 29 May a significant attack was put in against the 15th Battalion's position and they were briefly forced back before restoring the situation with a strong counterattack.

After this a period of stalemate fell across the peninsula. In early June, the 15th Battalion, its strength having fallen to below 600 men, was withdrawn from Quinn's Post to recuperate in a quiet sector known as "Rest Gully". Over the next two months, due to illness, the battalion's personnel were almost completely replaced. It received several drafts of reinforcements, amounting to over 500 men, including its transport element, and by early August it had reached a strength of 720 men. On 6 August, the Allies launched an offensive in an effort to try to break the deadlock, during which the 15th Battalion attacked the Abdel Rahman Bair heights, which was known to the Australians as "Hill 971", before later supporting the 14th Battalion's attack on "Hill 60". Casualties were heavy, and on 13 September the battalion was withdrawn for a brief rest on Lemnos, its strength having fallen to just 11 officers and 136 other ranks. They returned to Gallipoli early in November, occupying a position in Hay Valley, as winter began. They remained there until being evacuated on 13 December on the transport Carron, as part of the main Allied withdrawal. The battalion's casualties during the campaign amounted to 10 officers and 380 other ranks killed, and one officer and 17 other ranks captured.

Fighting on the Western Front Following the evacuation from Gallipoli, the AIF was re-organised in Egypt. This saw the splitting of the veteran battalions to provide cadres for new battalions as the AIF's infantry divisions in Egypt were doubled. As a part of this process, the 15th Battalion provided personnel to the 47th Battalion, and the 4th Brigade became part of the Australian 4th Division. After a further period of training, in June 1916 the battalion sailed for France aboard the transport Transylvania. After landing at Marseille, the 15th Battalion moved to northern France via rail to Beilleul, moving into the line around Bois Grenier for a brief period on 15 June. Amidst the carnage of the Battle of the Somme which was launched in July, the following month, the 15th Battalion was committed to fighting on the Western Front for the first time, entering the line around Pozières on 5 August, as the 4th Division relieved the shattered 2nd.

During the relief, the battalion suffered heavy shelling, which, after it had moved into trenches in front of the village along the sunken road to Courcellette, was followed by a brief German attack that was repulsed and resulted in the battalion capturing 20 Germans. In the days that followed, the battalion worked to improve their defensive line, digging saps towards the German trenches while patrols were sent out into no man's land. Late on 8 August, the 15th put in an attack alongside a British battalion from the Suffolk Regiment, on their left. Amidst heavy shelling and machine-gun crossfire, the attack stalled following the loss of almost all of the officers in the assaulting companies; nevertheless, despite progress on their left, they succeeded in capturing part of the German line, but were ordered to withdraw the following day. On the night of 9 August, a second attack was put in, in concert with the 16th Battalion, which succeeded in securing part of the German line, despite heavy shelling. At noon the following day, the 15th was relieved as the 4th Brigade was withdrawn from the line and replaced by the 13th. Casualties during the battalion's first battle on the Western Front were high: 90 killed and 370 wounded.

Following this, the 15th Battalion moved to Mouquet Farm, where they supported an attack by the 14th Battalion and carried out defensive duties. They remained there until early September, when they were withdrawn back to Warloy and then to Reingheist, via Doulens. Before this occurred, on 30 August, the 15th experienced a change in command, as Cannan, who had been promoted to brigadier-general, was replaced by Lieutenant Colonel Terence McSharry. The remainder of the year was spent in the Ypres salient, around St Eloi and Boorlartbeek, before winter fell on the Western Front. It was the worst winter in Europe in 40 years, and the men suffered heavily from sickness and the cold as they rotated through the line, conducting defensive duties and labouring before moving to Gueudecourt, and then later Lagnicourt, in the new year.

As winter passed, in an effort to shorten their lines and move into prepared positions, the Germans fell back towards the Hindenburg Line. After the Allies advanced to follow up the withdrawal, the battalion fought its first major battle of 1917 in early April, around Bullecourt, where the 4th Brigade attacked as a complete formation for the first time since Gallipoli. Committed without the protection of an artillery barrage, expecting tank support to win the day, the 4th Brigade suffered heavy casualties; on the first night, the tanks broke down and on the second, they had proven unable to breach the enemy defences, leaving the infantry to force their way through. After less than 10 hours of fighting, 2,339 soldiers from the 4th lay dead or wounded, out of 3,000 committed, including 400 from the 15th; by the end of the attack, only 52 men from the battalion's assault force remained uninjured. They were subsequently withdrawn from the line back to farmland around the village of Doulien where the battalion was rebuilt, eventually reaching a strength of 719 personnel of all ranks.

In mid-1917, the Australians were moved to Belgium as the focus of British operations shifted to the Ypres sector in an effort to draw German attention away from the French. The first effort came around Messines, on the southern flank, where a series of tunnels were dug under the German lines. On 7 June, 19 mines were detonated and in the ensuing fighting, the British captured Messines Ridge. Assigned a support role, the 15th Battalion was held in reserve and did not take part in the attack. The following day, it was committed to hold the gains that had been made during the attack, relieving the New Zealanders around Gooseberry Farm. The 15th remained in the Ypres sector and subsequently took part in the fighting around Polygon Wood during the Third Battle of Ypres in September. In November 1917, the battalion was withdrawn from the line for a three-month rest, spending the winter around Templeux-la-Fosse and Hollebeke.