The Galactic Padishah Empire encompassed the entire universe known to mankind. It was also commonly referred to as the Imperium, and later as the Old Imperium.
While the Padishah Emperor was seen as the Supreme ruler of the Known Universe, control of the Known Universe was shared, in a quasi-feudal arrangement, by the Landsraad, the Bene Gesserit, and the Spacing Guild.
The Imperium referred to the form of absolute trans-world governance used to maintain control of the Known Universe , typically before the rise of Leto Atreides II It provided a socioeconomic and political framework within the Faufreluches class system operated.
For more than 10,000 years the Imperium was headed by a ruling family or noble House, namely House Corrino. The Corrinos used political power and the superior force of its army to coerce or manipulate other significant political players such as the Bene Gesserit, the Spacing Guild, the Bene Tleilax, and the Landsraad.
The Imperium managed function through a delicate balance. The Emperor's military force was matched only by the sum of all the Lansdraad forces, and the Bene Gesserit, Bene Tleilax and the Spacing Guild provided services of their own. In this way, those that remained in power had to rely on others, otherwise the Imperium would fall into chaos.
Most economic ventures were conducted through CHOAM, the company in which the Imperial House, the Landsraad, and Bene Gesserit and the Spacing Guild all had a stake.
The League of Nobles began a slow evolution during The Butlerian Jihad, as it came to be dominated by Faykan Butler, as he merged the roles of the Viceroy and the Grand Patriarch into a heriditary title. After the final defeat of the Thinking Machine ruler, Omnius, and Faykin switched his last name to Corrino, the true structure of the Imperium began to take shape. For ten thousand years it was governed by House Corrino, the ruler of whom took the title of the Padishah Emperor of the Known Universe, since the Imperium spanned millions of planets over several galaxies.
In 10,193; House Atreides took control of the Imperium through Paul Atreides, who became Emperor and successor to Shaddam Corrino IV. Upon Paul's death, control passed briefly to his younger sister and Imperial Regent Alia Atreides.
After Alia's death, control of House Atreides, and thus the Imperium, passed to Paul's son Leto II. However, Leto's totalitarian form of rule saw a radical shift in the balance-of-power and structure of the Imperium.
Over the course of 3500 years, Leto's rule saw many changes to imperial society. Among these were:
- the dilution of power of the Great Houses, and a significant reduction in their numbers;
- populations forced to become almost entirely planet-bound;
- the erosion of the Fremen way of life;
- the outlawing of Mentats;
- the end of Wars of Assassins;
- the shift in ownership of the Bene Gesserit breeding program to the Imperial Seat;
- a significant increase in the use of Ixian technology by the Imperial Seat;
- the death of the Faufreluches system
Many more longstanding imperial institutions disappeared. The last vestiges of the Imperium effectively ended shortly after Leto's death, when The Scattering saw a mass exodus of humanity into unchartered space. The Imperium, the form of government that had kept humanity together for nearly 15,000 years, ended when Leto II plunged to his death into the Idaho River from a bridge far above.
Essentially, the remnants of the Imperium were inherited by Leto's Fish Speaker army, which appeared to continue to exist (though in a largely bastardised form) more than 1500 years after Leto's death. The planetary systems and galaxies within its borders were commonly referred to as the Old Imperium from that time onward. However, some institutions were not gone for good; approximately 1500 years after the death of the Imperium, Great Houses began to re-emerge from obscurity.
Behind the Scenes
After Leto's death, there appeared to be at least some planets within the Old Imperium that maintained their own form of government without Fish Speaker Involvement, such as Gammu which appeared to be under the control of the Bene Gesserit.