Whenever the trees are crying aloud,
And ships are tossed at sea,
By, on the highway, low and loud,
By at the gallop goes he.
— Robert Louis Stevenson, Windy Nights
Available only to those who have created the Aachen Palace Complex wonder, the Reiter is an experimental cavalry unit, consisting of a rider armed with a customised arquebus, and is meant to combine the speed of cavalry with the destructive armour-piercing qualities of arquebus shot. Even so, they are still as vulnerable as ranged cavalry to the same weapons as always (and not to mention expensive), although it must be noted that their armour gives them some semblance of protection so that they can escape melee battles. Plus, although they deal damage against most unarmoured units, they perform poorly against buildings and are subceptible against unique cavalry units which are normally prepared to deal with them. Like all ranged cavalry, Reiters are best used against units which are slow-moving and which cannot hit back easily, such as melee infantry and packed siege weapons.
Although experiments with horses and firearms took place far earlier with Giovanni de' Medici's Bande Nere (or "Black Bands") in 15th century Italy, it was in Germany, not Italy, that guns were first used extensively from horseback. The Reiters or "Schwarze Reiter" were experimental cavalry units raised by German armies during the early modern era, and consisted of bodies of armoured horsemen armed with swords and pistols. Although by the mid-16th century most cavalry units were picking up swords and pistols in place of heavy lances, they considered firearms as merely a secondary weapon — Reiters chose instead to use firearms as their primary weapon, as a means of sniping or skirmishing an enemy force in anticipation for a larger assault.