The Interstellar Dark Ages is the time period of approximately a millenium following the Final Wars and the devastation of civilization. Surviving societies underwent technological regression, and spaceborne trade and travel collapsed to near-zero.
  Its end is generally marked by the establishment of the Commonality, which started out as a union of the least-damaged or fastest-recovering powers. Elsewhere, the Interstellar Dark Ages did not end in most systems for decades or longer, and even in the modern times it is not unheard-of for a long-lost inhabited world, the result of some forgotten colonization effort, to be discovered again.