(covers information from Imperial Commonwealth of Planets)
The Palace of Unity is a large structure situated in the city of Rome, which rests on the Italic Peninsula of the planet Earth. It is the seat of power of both the Holy Empire of Solvada and the Imperial Commonwealth of Planets, as well as the residence of Emperor Ricarius Solivade.
The palace was built atop the former location of St. Peter's Basilica, which itself was torn down and replaced with a science academy in the early 23rd century. It was built to include a throne room, a meeting hall for the Commonwealth Assembly to convene in, living quarters for the Emperor, as well as various guests and staff, a military situation room, and other amenities.