Complex sentence: Meldrum's Force left Kh Fusail at midnight on 22 September with the Auckland Mounted Rifles Regiment as vanguard, followed by the 1st Battalion British West Indies Regiment, which dumped their kits and blankets to move "at once" towards Jisr ed Damieh.
Split into simpler sentences: Meldrum's Force left Kh Fusail at midnight on 22 September with the Auckland Mounted Rifles Regiment as vanguard. The battalion was ordered to dump their kits and blankets and move "at once" towards Jisr ed Damieh.