At the outbreak of the war August 1914  the Australian Government decided to raise the Australian Imperial Force (AIF) consisting of 20,000 troops comprising an infantry division and a light horse brigade of three regiments to be used at the discretion of Britain.
These regiments were raised from volunteers for overseas service, as the provisions of the Defence Act did not allow conscripts to be deployed overseas.
Nevertheless, many of the recruits were drawn from the various militia light horse formations created as a consequence of the Kitchener Report 1910 and the introduction of Universal Training, although they were assigned to freshly raised units that were separate to the light horse regiments raised as part of the militia.
Initial enlistments outstripped expectations and, as a result, a total of three light horse brigades as well as two divisional cavalry regiments were formed in the early part of the war.
Later, this was expanded to include a fourth light horse brigade, although this was broken up in mid-1915 to provide reinforcements to the troops deployed to Gallipoli and was not re-raised until early 1917.
After Gallipoli, the Australian light horse formations were used in the Middle Eastern theatre of World War I in the Sinai and Palestine Campaign.

The 5th Light Horse Brigade was raised as an AIF formation late in the war, coming into being in Palestine in mid-1918 as part of the expansion and reorganisation of the Desert Mounted Corps.
This expansion was made possible by the release of Indian cavalry troops from service in France and the disbandment of the Imperial Camel Corps, which resulted in enough Australian troops to raise several new light horse regiments.
Upon formation the brigade was commanded by Brigadier General George Macarthur-Onslow and consisted of two Australian Light Horse Regiments – the 14th and 15th – as well as a French cavalry regiment and a New Zealand machine gun squadron.
The brigade's artillery support was provided by the British who assigned B Battery, Honourable Artillery Company.


 
For the offensive in Palestine, the brigade was assigned to the Australian Mounted Division.
Prior to their commitment to operations, the troopers were converted from cameleers and were issued swords and received cavalry training.
Having been formed late in the war, the 5th Light Horse Brigade's involvement in combat operations was limited to the final offensive of the war, which began with the Battle of Megiddo in late September 1918.
During this offensive, the brigade took part in the Battle of Sharon and Battle of Tulkarm, taking a large number of prisoners to the west of the Samaria Ranges.
 During operations to secure Damascus,  the brigade took up positions overlooking the Barada Gorge, helping to cut off withdrawing Ottoman and German troops, and inflicting heavy casualties on them during an ambush on 30 September.
The brigade then spent the night there in freezing conditions before elements entered Damascus on 1 October.
For the remainder of the month, it was engaged in minor mopping up and patrol operations before joining the final stage of the campaign, which saw the brigade begin the advance towards Aleppo.
The advance was short lived, as on 30 October the Ottomans surrendered, and the Armistice of Mudros came into effect, bringing an end to the fighting in the theatre.
At the outbreak of the war August 1914  the Australian Government decided to raise the Australian Imperial Force (AIF) consisting of 20,000 troops comprising an infantry division and a light horse brigade of three regiments to be used at the discretion of Britain. These regiments were raised from volunteers for overseas service, as the provisions of the Defence Act did not allow conscripts to be deployed overseas. Nevertheless, many of the recruits were drawn from the various militia light horse formations created as a consequence of the Kitchener Report 1910 and the introduction of Universal Training, although they were assigned to freshly raised units that were separate to the light horse regiments raised as part of the militia. Initial enlistments outstripped expectations and, as a result, a total of three light horse brigades as well as two divisional cavalry regiments were formed in the early part of the war. Later, this was expanded to include a fourth light horse brigade, although this was broken up in mid-1915 to provide reinforcements to the troops deployed to Gallipoli and was not re-raised until early 1917. After Gallipoli, the Australian light horse formations were used in the Middle Eastern theatre of World War I in the Sinai and Palestine Campaign.
The 5th Light Horse Brigade was raised as an AIF formation late in the war, coming into being in Palestine in mid-1918 as part of the expansion and reorganisation of the Desert Mounted Corps. This expansion was made possible by the release of Indian cavalry troops from service in France and the disbandment of the Imperial Camel Corps, which resulted in enough Australian troops to raise several new light horse regiments. Upon formation the brigade was commanded by Brigadier General George Macarthur-Onslow and consisted of two Australian Light Horse Regiments – the 14th and 15th – as well as a French cavalry regiment and a New Zealand machine gun squadron. The brigade's artillery support was provided by the British who assigned B Battery, Honourable Artillery Company.

 
For the offensive in Palestine, the brigade was assigned to the Australian Mounted Division. Prior to their commitment to operations, the troopers were converted from cameleers and were issued swords and received cavalry training. Having been formed late in the war, the 5th Light Horse Brigade's involvement in combat operations was limited to the final offensive of the war, which began with the Battle of Megiddo in late September 1918. During this offensive, the brigade took part in the Battle of Sharon and Battle of Tulkarm, taking a large number of prisoners to the west of the Samaria Ranges.  During operations to secure Damascus,  the brigade took up positions overlooking the Barada Gorge, helping to cut off withdrawing Ottoman and German troops, and inflicting heavy casualties on them during an ambush on 30 September. The brigade then spent the night there in freezing conditions before elements entered Damascus on 1 October. For the remainder of the month, it was engaged in minor mopping up and patrol operations before joining the final stage of the campaign, which saw the brigade begin the advance towards Aleppo. The advance was short lived, as on 30 October the Ottomans surrendered, and the Armistice of Mudros came into effect, bringing an end to the fighting in the theatre.
5th Light Horse Brigade