The world of Aquilon is primarily covered with icy mountains peopled by hearty and self-reliant barbarian tribes. These warriors fight on foot, as cavalry or chariots flounder in such rocky terrain. The Executioners raised from these people share this predilection and, as these warriors constitute the bulk of the Chapter’s recruits, the Executioners field relatively few squads equipped with jump packs or bikes.
However, Aquilon is not entirely covered in mountains. It has equatorial plains peopled by such tribes as the Kush, Shem, and Hyrkanians. Though not as robust as the mountain tribes, these plainsmen are still able to defend their comparatively lush plains. They have developed a nomadic culture based on the horses introduced by early human settlers. Their warriors move swiftly across the plains, attacking other plains tribes, tracking herds of game animals, and rapidly encircling any raiders from the mountains. Over the millennia, each of these plains tribes has developed their own bloodlines of horses according to their preferences.