When man realizes that he can ride on a horse (instead of just using it as a work engine), he becomes a true monster out of legend. A whole new class of weapons is born, - fast, maneuverable and difficult to kill, which will create headaches for generals for millennia to come. This class is also supported by its own building in the Encampment - the Stable. Prior to the February 2017 update Horseback Riding had Animal Husbandry as its prerequirement technology.