The Adrexi were always a bit violent, but when a new government seized power, we had little choice but to launch an intervention.
—Arius Valdayn
The Dominion of Adrex, also known as the Imperium of Adrex or the Adrexi Imperium, sometimes more archaically spelled Hadrex(i), was the official, interstellar government of the Adrexi species, formed prior to the disappearance of the Ethereal Empire from the Empire of Hadrex and the Adrexi Republic. The two had long been at war, vying for dominance of their homeworld, until finally, the Republic's legislature submitted a unification proposal to the Empire. Against the desires of the Imperial leadership, the then-reigning Emperor of Adrex agreed to the proposal, bringing about the Dominion of Adrex.
Following the Ethereal Empire's disappearance, the Dominion of Adrex was among the first non-Ethereal Human governments to join the Ethereal Demesnes' new regional legislature, the Diet, sending their first delegation not long after its foundation. In spite of being a relatively imperial government, the Dominion was categorized in the Diet's official imperial roll as a core Democratic Demesne, as both the legislature and executive were, by this time, fully elected directly by the Adrexi people.
The Adrexi were one of the few non-Ethereal Human states of the Ethereal Demesnes to be able to compete militarily with them, in fact forming an important armed guard against potential foreign invaders such as the Sith, the Confederacy of Independent Systems and the Galactic Empire. However, not long prior to the Galactic Civil War, Imperial Navy admiral and heir to leadership of the Demesnes Arius Valdayn felt he was "forced" to intervene when a militarist faction of Adrexi seized control of the government, threatening military conflict and violent expansion against neighboring star systems. Subsequently, forces under Valdayn's command forced the militarists to surrender, reinstating the rightfully-elected Adrexi government.