The Ultima Segmentum (or Segmentum Ultima) is one of the Segmentae into which the Imperium divides the galaxy. It lies to the east of Holy Terra, and its Segmentum Capital is located at Kar Duniash. The Galactic Core, the Maelstrom and the Eastern Fringe all lie within the Ultima Segmentum.
The Eastern Fringe
At the edge of the Galaxy, at the limits of the Astronomicon, lies the Eastern Fringe. The noble worlds of Ultramar, the great forge of Triplex Phall and the great shrines of Okassis lie among these stars, but xeno enclaves such as the Tau Empire, several Eldar Craftworlds, and innumerable other threats both ancient and new dot the void. It is here, at the very edge of Imperial space, that the Ruhrort Sector is located.