Horse Archers - a basic cavalry unit capable of outpacing infantry, while peppering them with arrows. Horse archers have a blind spot on their right. They deal mediocre damage, but in massive groups can overwhelm enemies with saturation fireb thanks to their good rate of attack and range.
It is unknown when exactly the practice of horse archery began, but it has been often associated with cultures in Central Asia, where various nomadic tribes made their living off the practice of animal herding and horses ever since the prehistoric period. The land lends itself to breed a people who were used to harsh living conditions and mobility.