Victory by 800 mounted Australians over 4,000 well-trained Turks seems a bit far-fetched. But that's exactly what happened on October 31, 1917, at the Battle of Beersheba, which 90 years ago arguably changed the direction of the Sinai and Palestine campaign during World War I.

It was a day of surprises for the Turks, one that had been planned far in advance: Already in May 1917, General Philip Chetwode wrote his Notes on the Palestine Campaign, which outlined a suggested plan of attack. There he suggested that the approaching Third Battle of Gaza should move inland and center around a relatively loosely guarded east flank of Beersheba. The Turks, he suggested, would not anticipate the mounted attack due to the scarcity of water for horses and soldiers alike. Chetwode, however, claimed that it would be easier and more efficient to secretly engineer water access to the area than to break through the more heavily guarded Gaza area.