Horseman is the very first cavalry in the game. Having the highest speed in Bronze Age but moderate attack and defense. They don't have any terrain bonus. Effective against Short Range Class, has chance to 1 hit kill Slinger.
Vulnerable to light infantry class as light infantry have bonus against cavalry. They are always the first units to have action and able to reach another end of the map in 2 turns. Thus, very useful to counter both short range and artillery classes. However, they cannot pass though water or rocks terrain. It can be used as decoy to distract enemies by moving to another corner of the map that is away from the main army.
A horseman encounter with spearfighters. It is recommended to move away instead of fighting with them.