the 51st battalion was originally raised in egypt in early 1916 as part of the reorganisation and expansion of the aif following the gallipoli campaign. this was achieved by transferring cadres of experienced personnel predominately from units of the 1st division to the newly formed battalions and combining them with recently recruited personnel who had been dispatched as reinforcements from australia. the unit's first intake of personnel were drawn from men originating from western australia, many of whom had already served with the 11th battalion during the fighting in turkey. as a result, at the time of its formation, it inherited the battle honour awarded to the mounted infantry from western australia who served during the second boer war.