Tarsis is the home and Throne-World of all mankind, and the spiritual center of the New Faith. It is the center of the World economy as well; a Thyrendi merchant once estimated that two-thirds of the World's wealth resided on Tarsis.
The Tarsins of the elder days were clearly concerned with security, and placed a great array of fortresses in orbit. These were armed with weapons beyond modern understanding, arcane machinery that can no longer be understood with the current sciences available to mortal men. For ten thousand years, these fortresses have safeguarded Tarsis from without, but not from within. The only foe ever to capture Tarsis was Hâlǔmǎr, the Shadow Emperor, who took Tarsis without firing a shot. He later tried to turn these fortresses against the Savior, but to no avail. To this day, no enemy of man has ever braved the great array and lived to tell the tale.
Tarsis's unassailability has been a great boon for the Coalition, ensuring that the center of political, religious, and economic life in the Coalition can go unscathed no matter how dire the situation beyond gets. Many a chronicler has written a thesis on the guaranteed safety of Tarsis effecting the long-term stability of the Empire.