Publius is the old homeworld of the Neo-Terran Intergalactic Hegemony. Publius was annexed by the confederacy in 4740, and was controlled by them until the Treaty of Cuicul, where Publius along with a few other Neo-Terran Holy Worlds were handed to the Neo-Terran Government. The surface of Publius is covered in megacities, to the point where you can no longer see the planets natural Biosphere from orbit.
The Publius Massacre
In the latter part of the Confederate-Publian war, publius became under seige for 2 years straight. Orbital bombardment scarred the planet permanently, and to this day you can still find craters and old city ruins.