Parthian

The king’s cavalry are also trained to an exercise called the keykaj, which consists in turning about on the saddle at full speed and firing a carbine backward. This they learn from their childhood, and it gives them great confidence and dexterity on horseback. It is probably a remnant of the old Parthian custom so frequently alluded to in ancient authors; with this difference, that fire-arms are now used instead of bows and arrows.

a Parthian shot