The Centauri are a humanoid species in the fictional universe of the Babylon 5 television series. They were the first alien species to make open contact with the human race. Their homeworld is Centauri Prime, a small Earth-like planet consisting of two large continents and several smaller islands divided by large oceans of water. The government of the Centauri Republic is, despite it being called a republic, ruled by an Emperor and an assembly of Ministers and heads of various Houses that form the Centaurum. Despite the name, the Centauri are neither from nor associated with the Alpha Centauri star system (within the context of Babylon 5, this inaccurate naming is explained as having resulted from a mistranslation during first contact between humans and the Centauri; however, there are also a number of other stars named Centauri).
Centauri Prime is the homeworld of the Centauri and throne of the once-expansive Centauri Republic. Centauri Prime has fewer land masses than Earth; there are only two main continents with an abundance of small islands and extensive marine habitats. The planet has a population of about three billion, or considerably less than the homeworlds of many other alien races.
In 2260-61, one of the islands in the southern hemisphere of the planet was used as a staging ground for Shadow ships and personnel, until, in late 2261, then-Prime Minister Londo Mollari destroyed this island using fusion-based nuclear bombs.
The only real check on the monarch's power resides in the Centarum, an assembly of the leaders of the major noble houses. Nobles able to manipulate the Centarum successfully are able to wield great power. The Centarum can vote to overturn a decree of the monarch; although this would appear to be a rare practice. An exception to the power of the Centarum came about during the brief reign of the Emperor Cartagia, whose personal madness drove him to have his enemies in the Centarum assassinated, allowing him to rule despotically. The Centauri seemed culturally obsessed with rank, social position, wealth, and power. They were quite Machiavellian in their political games and treachery. Everything seemed to involve strategic moves and counter moves, strategy games "for keeps" with covert or overt ruthlessness.
The Centauri Republic reflects many imperial cultures of Earth, though J. Michael Straczynski specifically makes the comparison with "the British Empire once upon a time... It was a great military power. But slowly, as can happen, they grew content, and lazy, and gradually their own empire began to slip between their fingers.". In the movie The Gathering, Babylon 5 Ambassador Londo Mollari laments that Centauri Prime has been reduced to "A tourist attraction... See the Centauri Republic, nine to five... Earth time".
Around the earth year 3000 B.C. the first true Centauri civilization appeared. This rapid burst of technological development was the result of competition with another sapient species on their world called the Xon. At first isolated by oceans, when the two species finally did meet the result was a bloody war of genocide and attrition. First contact occurred when a Centauri expedition of three vessels happened upon a Xon coastal city. The vessels returned to the Centauri continent, carrying a Xon invasion force (its original Centauri crew having been slaughtered).
As the Centauri entered a historical period similar to the Renaissance, around the earth year 738 BC, the Xon began attacking and raiding Centauri villages in small-scale regional wars. The Xon, riding high on these easy victories, then began a massive campaign to dominate the Centauri on a global scale. The Centauri-Xon war would last for a thousand years, and would nearly lead to the extinction of the Centauri. Although technologically inferior to the Centauri, the Xon were physically larger and stronger than the Centauri and possessed superior endurance.
Though battles raged across the planet's surface, destroying whole cities and depopulating entire regions (both Centauri and Xon), the conflict drove the Centauri to greatly advance their level of technology, exceeding the limited capabilities of the Xon and eventually giving them the upper hand in the fighting. By the earth year 262 A.D. the Xon were eradicated from the face of the planet. By this time the Centauri Republic had obtained an Industrial Age equivalent to Earth at the beginning of the 20th century.
Defeat of the Xon gave rise to the current class structure of modern Centauri society. Centauri families who had done the bulk of the fighting, and had the most survivors at the end of the war, became the great houses of the Centauri. This new government of nobles created the Centaurum. The nobles appointed Lord Tuscano, who led the war against the Xon, to the position of Emperor. These noble families would maintain their power and privileges for hundreds of years, even after the planet's population had grown into the billions. Furthermore, Centauri females were relegated into the roles of mothers and housewives, as the nobles believed that females needed to focus on bearing children and rebuilding the population instead of competing with males for power and social position. Even in the 23rd Century, Centauri females are discouraged from seeking power or careers for themselves – though many females are the "power behind the throne" in their houses, skilled in deception and manipulation. The widows of many powerful leaders are often considered conduits to their deceased spouses, and wield impressive power.
The Shoggren attempted to invade Centauri Prime in the last years of Tuscano's rule, but were defeated. The technology acquired from the invaders and the discovery of a Jumpgate in the Centauri system allowed the Centauri to leap ahead technologically and begin the modern Centauri Republic's interstellar conquests.
Although the Centauri population did eventually grow, by the time the Babylon 5 station opened in 2257 A.D. the population of Centauri Prime was only three billion, considerably less than that of the galaxy's other major planets, such as Earth, Narn, or Minbar. However this is a little over a fifth of the fourteen billion Centauri that Adira says Londo will eventually rule in "Day Of The Dead". Having a minority of the population on the homeworld is a legacy of the Centauri's rapid interstellar expansion while their own population was still quite small, and the many centuries that have passed since that time - the populations of some older Centauri colonies are comparable to that of Centauri Prime.
The Centauri Republic quickly began a period of expansion spanning the centuries before the second Shadow War and the birth of the Interstellar Alliance. The Centauri first left their homeworld just as the first Shadow War was ending and consequently played no part in that struggle. Ships and some outposts fell to the Drakh suggesting the Centauri did encounter Shadow forces to a limited degree. These defeats were stricken from public record by the Emperor's order, yet surviving crewmen and colonial defenders brought stories back to Centauri Prime.
At its greatest extent, hundreds of worlds were subject to the Centauri Republic, hence its epithet, 'Lion of the Galaxy'. The occupation of the Narn homeworld began in the early 22nd Century. For the next hundred years the agrarian and technologically primitive Narns were exploited and their world stripped of resources. The Centauri withdrew a hundred years later in the face of growing Narn resistance (see Narn Regime). By 2258 the Centauri Empire had dwindled to a few colony worlds and Centauri Prime itself, seemingly more through the growing apathy and decadence of the Republic than military inferiority.
The revival of Centauri power and territory was made possible by their covert alliance with the Shadows, an ancient and extremely powerful alien race which was using the Centauri for their own ends. The Shadows were allowed to base a fleet of their ships on an island on Centauri Prime by the Centauri Emperor Cartagia. This move nearly led to the total destruction of Centauri Prime by a massive Vorlon warship which had traveled to Centauri space to eradicate any Shadow influence from the planet. The Shadow vessels were destroyed by Londo Mollari, the acting Prime Minister, and the planet was saved. However, by 2261 the Shadows had departed the galaxy along with the Vorlons and other First Ones. The Shadow's former servants and soldiers, the Drakh, were driven from their homeworld by the forces of Captain John Sheridan and the Interstellar Alliance. The Drakh decided to secretly settle on Centauri Prime, which they remembered from the Shadow occupation under Cartagia, and make it their new home. The Drakh secretly gained control of the Regent and used him to start a war with the other worlds of the Interstellar Alliance in 2262. The destruction of civilian shipping by the Drakh was blamed on the Centauri. Thanks to the Drakh's random attacks on alien shipping, almost every other race fought the Centauri during the war, leaving them almost completely isolated, which was the Drakh's intention. Near the end of the conflict a large force of Narn and Drazi warships made for Centauri Prime, while Drakh agents forced the Regent to deactivate the planetary defences and send any warships defending the planet away on a false mission. The Narn-Drazi fleet bombarded Centauri Prime and the planet was laid waste, with most of its major cities reduced to rubble and many civilians killed. The Drakh then forced Londo Mollari to accept their secret control of Centauri Prime by threatening to detonate nuclear bombs hidden under the planet's major cities, which would have killed billions more people and totally destroyed Centauri civilization. The Regent was then killed, and Londo was crowned the Emperor of the Centauri, but he was merely a puppet for the Drakh. Under the Drakh's direction the Centauri severed all relations with the Interstellar Alliance. By 2278 little was left of the grandeur of the Centauri save their pride, their patriotism, and their determination to rebuild their devastated planet.
Centauri males of high social status typically wear their hair in Peacock-tail shaped fans, the length and style of which are determined by relative social class. Low-class Centauri males have not been seen without helmets. Females typically shave their heads, but some females maintain a knot of hair that grows from the backs of their heads. The social significance (if any) of complete versus almost-complete baldness on a female is unknown.
Their dress and customs reflect their imperialistic culture, with militaristic clothing reminiscent of the 18th Century for the men, gowns for the women whose design appears to be of similar general vintage, and a generally courtly manner one would expect to find in Victorian England (without the Puritanical streak) or Imperial France (with the associated decadence).
A number of Centauri have telepathic ability. Like humans, the degree of telepathic ability varies with the individual. Unlike humans, who have had proven telepaths for only a few generations, Centauri possess a far greater understanding of the skill, and permit those who possess it far more latitude. The Telepath's Guild is a respected institution, and the skill of their average members is great enough to overcome Mindwipes.
The Centauri Emperor was rarely seen without the Imperial Tetrapathy – a quartet of female telepaths who have maintained a telepathic link since infancy. This link is thus so strong that it has effectively unlimited range. Whenever the Emperor leaves Centauri Prime, two of the Tetrapathy accompanied him and two remained at the royal palace, allowing rapid communication between the Emperor and the homeworld at all times. This, however, changed upon the accession of Emperor Cartagia, who had them executed as one of his first official acts.