From Smith, Men of Beersheba (1993) pp 3 - 4:
On 11th August (1914) authority was promulgated for the formation of the 4th Light horse regiment as Divisional Cavalry for the 1st Australian Division under the command of Lieutenant Colonel John Forsyth. This fine officer however was soon detached to the 1st Light Horse Brigade and did not assume command of his regiment until the troops arrived in Egypt. At the Broadmeadows camp the Regiment's replacement commander, Lieutenant Colonel Long set about recruiting, organising, equipping and training his fledgling Regiment."
AWM photo titled 1914 Broadmeadows. Horse lines of Light horse units training. (H03025)
From Smith, Men of Beersheba (1993) p 4:
"It is often asserted that the bulk of the light horse regiments found their recruits in rural areas this is not entirely true. Certainly many troopers had backgrounds on the land which suits the modern perception that light horsemen were tall, bronzed young men accustomed to life in the saddle on the outback plains of Australia. But an examination of recruiting sources for the 4th Light Horse Regiment reveals that this is not the case…of the original members of the regiment, about 20% were city dwellers from Melbourne."
The Light Horse Regiment was made up as follows:
Year/Unit:1916 Light HorseRegiment
Section: 4 Other Ranks (mounted)
Troop: Troop Headquarters (1 Officer, 3 Other Ranks)
8 x sections (ie 32 Other Ranks)
Squadron: 4 x troops.
Total:4 Officers,140 Other Ranks
Regiment: 25 Officers,497 Other Ranks
Regimental HQ3 x squadron
897 Other Ranks