A horse archer is a cavalryman armed with a bow, able to shoot while riding from horseback. Archery has occasionally been used from the backs of other riding animals. In large open areas, it was a highly successful technique for hunting, for protecting the herds, and for war. It was a defining characteristic of the Eurasian nomads during antiquity and the medieval period, as well as the Iranian peoples (Scythians, Sarmatians, Parthians, Sassanid Persians) and Indians in antiquity, and by the Mongols and the Turkic peoples during the Middle Ages. By the expansion of these peoples, the practice also spread to Eastern Europe (via the Sarmatians and the Huns), to Mesopotamia, and to East Asia. In East Asia, horse archery came to be particularly honoured in the samurai tradition of Japan, where horse archery is called Yabusame.
The term mounted archer occurs in medieval English sources to describe a soldier who rode to battle but who dismounted to shoot. In the modern English usage, however, "mounted archer" and "horse archer" are essentially interchangeable terms
Horse archery developed separately among the peoples of the South American pampas and the North American prairies; the Comanches were especially skilled.
Since using a bow requires the rider to let go of the reins with both hands, horse archers need superb equestrian skills if they are to shoot on the move. The natives of large grassland areas used mounted archery for hunting, for protecting their herds, and for war. Horse archery was for many groups a basic survival skill, and additionally made each able-bodied man, at need, a highly-mobile warrior. The buffalo hunts of the North American prairies may be the best-recorded examples of bowhunting by mounted archers.