The Centauri Republic is a powerful nation state in the Babylon 5 universe.
Centauri are very similar to humans in appearance, and they have similar strength, endurance, and agility. They have many internal differences, however, including radically different circulatory and reproductive systems. The species produces telepaths, although the frequency of Centauri telepaths in comparison to Human telepaths or the other Young Races is unknown. Precognitive ability is also known among the Centauri: many Centauri have accurate dreams about the circumstances under which they will die, and Centauri seeresses like Lady Morella are able to make accurate, conditional predictions about future events.
The Centauri Republic is governed from a capital city on Centauri Prime. Despite the name, the government appears to be a constitutional monarchy, with a senate-like body called the “Centaurum” and a semi-hereditary Emperor. The highest officer of the Centaurum is the Prime Minister.
One function of the Centaurum is to elect/appoint the Republic’s Emperor, who seems to have considerable political authority in the Republic, serving as head of state, head of government, and commander-in-chief of the armed forces. The exact restrictions on the Emperor’s powers aren’t clear; the Emperor seems to wield most of the political power in the Centauri Republic, but the Centaurum can overrule the Emperor’s decisions in unspecified circumstances. While the Centaurum often appoints a related "heir" from the past Emperor's family, there is no indication that this is a requirement (although this is difficult to say for sure, the last three Emperors – Turhan, Cartagia, and Mollari – left no heirs of the body).
The Centauri Republic was once a widespread empire, controlling many worlds in navigable space, but the empire has been in decline for centuries. Within the last few decades they lost control of Narn in an uprising, after heavily over-mining the planet's resources.
The Centauri were notable for being the first species to establish contact with humanity as well as providing mankind with hyperspace technology via trade.
The Centauri Republic was known to be in control of 12 worlds in 2258, but the extent of their territory fluctuated over the next four years as they fought wars against the Narn Regime, members of the League of Non-Aligned Worlds, and -- later -- members of the Interstellar Alliance. For example, the Narn Regime surrendered to them unconditionally in late 2259, giving them at least nominal control of all Narn territory, but they gave up at least some of that territory (Narn itself, if nothing else) in 2261. The extent of their territory in 2262 and later is unknown. Other worlds known to have been under Centauri control during the series include Ragesh III and Gorash VII.
The Centauri Republic is a military power comparable to the Earth Alliance and Narn Regime in Babylon 5. Among the Young Races, they are technologically second only to the Minbari Federation, but the "fire" went out of them decades ago and the Republic had shrunk from its greatest extent to a mere twelve worlds by 2258. This qualifies them as an insignificant power by Star Wars standards and a minor power by Star Trek standards.
Centauri of Note
- Londo Mollari
- Vir Cotto