Located on the Eastern Fringe of the galaxy, the T'au Empire is a young empire composed of many xenos races, including the T'au themselves. Though young compared to the other major powers in the constant wars in the galaxy, the T'au Empire is rapidly expanding, determined to unite the galaxy under their philosophy, the Greater Good. T'au society is divided into five castes: The Fire Caste, the T'au Empire's military ground forces; the Earth Caste, the engineers, laborers, and scientists; the Water Caste, the diplomats, storytellers, administrators, and bureaucrats; the Air Caste, the military naval forces and merchant fleets of the Empire; and the mysterious Ethereal Caste, the leaders of the Empire. The T'au possess highly advanced weapons, as well as sophisticated battlesuit technology. However, the Empire's Fire Warriors are poor melee fighters. Fortunately, their expert marksmanship more than makes up for it. The T'au Empire is also assisted by auxiliary forces from other races: The Kroot, savage xenos who absorb the traits of their foes by eating their corpses, and are excellent melee fighters; the Vespid, insectoid aliens who were among the first species to join the Empire; humans referred to the T'au as Gue'vesa, who serve as auxiliaries in the Fire Caste; the Nicassar, an ursine species with psychic abilities and the very first species to join the Empire; the Demiurg, a diminutive race of miners; the Tarellians, dog-like aliens who often serve the T'au Empire as mercenaries; the Galg, amphibious aliens who also frequently serve as mercenaries; other member species include the Ji'atrix, Morralian, Ranghon, and Hrenian.