The galaxy contains some four hundred thousand million stars. Only a fraction 
are presumed to have habitable planetary systems, and only a fraction of these 
have been investigated. Most are situated within the spiral arms between ten and 
forty thousand light years from the galactic center. Even the human controlled 
Imperium, by far the largest and most widely distributed of all stellar empires, 
contains only a tiny fraction of the galaxy's stars. 

   Humanity is one of many races in the galaxy, but none are so widely distributed
or so numerous as humans. Most occupy only a single world or a small group of
worlds. Only a few alien races possess technology which rivals that of the
Imperium - Orks, Eldar and Tyranids.

   This is a time of superstition, in which unfathomable technology has been
enslaved to the forces of mysticism and madness. To ordinary humans, scientific
thought represents an abhorrent perversity, a corruption of honor and religious
virtue. Even to those who deal with technology, science and magic have become 
inseparable. Warp engines must have runes engraved upon their sides, and lasers
require the blessing of the Gods of Battle. 

   This is a universe in which the gods, mysticism and magic are real.