In the wake of the Fall of the Interplanetary Dominion of Earth, a group of settled planets decided to form the Solar Empire, on the basis of "resisting the corruption of unnatural and pagan life forms." At the center of the Solar Empire is the Unitary, the ruling body, made up of the Triumvirate (the ruling branch, with the First Sun, the Second Sun, and the Third Sun), the Concilium (the legislative branch), and the Stellar Chamber (the judicial branch, made up of Magistrates). The main military arm of the Solar Empire is the Solar Defense Forces (SDF). With their policy of protecting the Solar Empire from any and all threats, they have been both the defenders and instigators of wars, including the Solar-Sylvan War, the Shifters War, and the Six-Sided War. In most cases, the Solar Empire has come out on top, mainly because of superior technology and the sheer scale of the SDF. The sole exception is the Six-Sided War, which resulted in a stalemate, but only after a number of Solar worlds had been devastated by orbital bombardment or ravaged by famine and disease. The current war is an ongoing one, called by the SDF the Strange War (due to many of their targets being magical worlds controlled by the Mysterium Majestic). Others call it the Sword and Cup War, for unknown reasons. An apparent secret branch of the SDF called the Penumbra exists. What their purpose is is unknown.