Elephant-Back Duel Day. It falls on the 18th of January. It was on this day in 1592 A.D. that King Naresuan the Great engaged the Deputy King of Burma in an elephant-back duel which ended in the defeat and slaying of the latter. In ancient times in this part of the world, elephants were used in battle instead of horses. When the commanders of the two armies fought in a duel on elephant-back, it was a decisive battle of the top level. In such a fight, not only the victor gained the supreme honour, even the vanquished was esteemed a true warrior.