What IS horse archery you ask? According to Wikipedia…
“A horse archer or mounted archer is a cavalryman armed with a bow, able to shoot while riding from horseback. 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, including Iranian peoples (Scythians, Sarmatians, Sassanids) 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 mounted archery is called Yabusame.
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. Mounted 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.
In battle, light horse archers were typically skirmishers, lightly armed missile troops capable of moving swiftly to avoid close combat or to deliver a rapid blow to the flanks or rear of the foe.
In the tactic of the Parthian shot the rider would retreat from the enemy while turning his upper body and shooting backwards. Due to the superior speed of mounted archers, troops under attack from horse archers were unable to respond to the threat if they did not have ranged weapons of their own.
Horse archers may be either light, such as Scythian, Hun, or Parthian horsemen, or heavy, such as Byzantine kavallarioi, Turkish timariots, Russian druzhina and Japanese samurai. Heavy horse archers typically fought as disciplined units. Instead of harassing without ever making contact, they shot in volleys, weakening the enemy before they charged. In addition to bows, they often also carried close combat weapons, such as lances or spears. Some nations, like medieval Mongols, Hungarians and Cumans fielded both light and heavy mounted archers. In some armies, such as those of the Parthians, Palmyrans, and the Teutonic Order of Knights, the mounted troops consisted of both super-heavy troops (cataphracts, knights) without bows, and light mounted archers.
The earliest depictions of mounted archers are found in artwork of the Neo-Assyrian Empire of about the 9th century BC and reflects the incursions of the early Iranian peoples. Early horse archery, depicted on the Assyrian carvings, involved two riders, one controlling both horses while the second shot.
Heavy horse archers first appeared in the Assyrian army in the 7th century BC after abandoning chariot warfare and formed a link between light skirmishing cavalrymen and heavy cataphract cavalry. The heavy horse archers usually had mail or lamellar armour and helmets, and sometimes even their horses were armoured. Heavy horse archers, instead of skirmishing and hit-and-run tactics, formed in disciplined formations and units, sometimes intermixed with lancers as in Byzantine and Turkish armies, and shot as volleys instead of shooting as individuals. The usual tactic was to first shoot five or six volleys at the enemy to weaken him and to disorganise them, and then charge. Heavy horse archers often carried spears or lances for close combat, or formed mixed units with lancers. The Mongol armies and others included both heavy and light horse archers.
Heavy horse archers could usually outshoot their light counterparts, and wearing armour, could stand their shooting. The Russian druzhina cavalry developed as a countermeasure to the Tatar light troops. Likewise, the Turkish timariots and qapikulu were often as heavily armoured as Western knights, and could stand the Hungarian, Albanian and Mongol horse archers.
The German and Scandinavian Medieval armies made extensive use of mounted crossbowmen. They would act not only as scouts and skirmishers, but also protecting the flanks of the knights and infantry, and chasing away the enemy light cavalry. When the battle was fully engaged, they would charge at the enemy flank, shoot a single devastating volley at point-blank range and then attack the enemy with swords, without reloading.
Horse archers were eventually rendered obsolete by the development of modern firearms. In the 16th and subsequent centuries, various cavalry forces armed with firearms gradually started appearing. Because the conventional arquebus and musket were too awkward for a cavalryman to use, lighter weapons such as the carbine had to be developed, that could be effectively used from horseback, much in the same manner as the composite recurve bow presumably developed from earlier bows. The Comanches of North America found their bows more effective than muzzle loading guns. “After… about 1800, most Comanches began to discard muskets and pistols and to rely on their older weapons.” Bows were still used in the fighting that ended the freedom of Native Americans in the United States, but almost all warriors who had immediate access to modern repeating firearms used these guns instead.