The histories of the three systems that make up Tri-System space - Irrulan, Isaac and Hom - have long been intertwined. Although separate systems, they are all within a few local jumps of each other, and the cultures and inhabitants of all three have been connected ever since travel outside local planetary space became possible. A century ago, the development of jump gate technology made long-distance travel between systems feasible. However, jump gate construction was prohibitively expensive, and the Tri-System government could not set aside the needed funds. As piracy along conventional nav routes increased, so did public clamor for system jumps.

    The Irrulan System is somewhat twofold in nature. On one hand, it contains the overcrowded, overdeveloped, thoroughly urban Hermes. On the other are the peaceful backwater populations of Bex and Destinas and a number of small, barely populated planets, valued only for their isolation or mineral resources.

    Isaac is a problematic system, acting as a center for the Tri-System elite and a convenient drop-site for its least desirable. Both the Tri-System government and CIS are based here.

    The oldest and youngest civilizations of the Tri-System are located in Hom. It is home base for more than its fair share of mercenaries and pilots, and therefore boasts a lower incidence of piracy than its two sister systems.