(covers information from several alternate timelines)
|Satellites:||At least one moon|
|Affiliation:||Romulan Star Empire|
"I have been to over a hundred different worlds, and none possess the awesome beauty of Romulus."
Romulus was the inhabited second planet of the Romulan system, which was located in Sector Z-6 of the Alpha Quadrant. It had at least one moon and was the homeworld of the Romulans as well as the capital of the Romulan Star Empire before its destruction in 2387.
The location of Romulus has been depicted on several star charts. In 2266, the location of Romulus was seen on the Sector Z-6 star chart. (TOS: "Balance of Terror", display graphic) In 2293, the location of Romulus in the Milky Way Galaxy was depicted on a Federation star chart. (Star Trek VI: The Undiscovered Country, production art)
- See also: Romulan history
Romulus was an uninhabited world and was suitable for colonization by humanoid lifeforms. In the 4th century, a group of Vulcans left their homeworld Vulcan and settled the planets Calder II, Dessica II, Draken IV, Yadalla Prime, and Barradas III. This civilization, called the Debrune, was regarded as a predecessor of the Romulan Star Empire. After their odyssey, which lasted for centuries, the Vulcans finally reached Romulus, a planet that matched all their needs and seemed as a perfect place to begin a new civilization. (TNG: "Gambit, Part I", "Gambit, Part II")
During his time as an Obsidian Order operative, Elim Garak worked at the Cardassian embassy on Romulus as a gardener. He claimed the dominant color there to be grey. (DS9: "Broken Link", "Inter Arma Enim Silent Leges")
In Grathon Tolar's forged holoprogram, a hologram of Weyoun stated that the Founders believed that they would be on Romulus in less than three weeks after a Dominion invasion. (DS9: "In the Pale Moonlight")
During the Dominion War, injured Romulan soldiers were taken to Romulus for treatment, until Senator Kimara Cretak successfully persuaded the Bajorans to let them establish a hospital on Derna. (DS9: "Image in the Sand")
In 2387, a star close to Romulus went supernova, endangering the entire galaxy. Ambassador Spock created a red matter singularity which consumed the star, but not before the supernova reached Romulus, destroying the planet. (Star Trek)
In an alternate future (c. 2395) experienced by Jean-Luc Picard in 2370, Romulus and the Romulan Empire had been conquered by the Klingons. Romulus was cut off from the Federation, except for the occasional medical ships allowed through to help stop an outbreak of Tarellian plague. (TNG: "All Good Things...")
Cities and towns:
In Roman mythology, Romulus and his brother Remus were known as the brothers who founded the city of Rome. Romulus became the first king after killing his brother. The relation between the planets of Romulus and Remus reflect this. See Romulus and Remus.
Production designer Herman Zimmerman commented in Star Trek: The Magazine about his work during Star Trek Nemesis: "The Romulans have possessed advanced technology a lot longer than the Federation, so the look was a combination of art deco and medievalism meets high tech. Most of the designs were inspired by Italian designer Carlo Scarpa."
Regarding exterior design of the Senate area, designer Syd Dutton said director "Stuart Baird wanted us to think about Albert Speer, the architect who did all the conceptual drawings for Hitler. Speer took that national socialist idea to a ridiculous extreme where everything was huge and classical." "The Romulans are a people who live in a marshy area. They had little houses on stilts around mudwork. The mudwork became part of this central core and that was where the old part of the city – the Forum and Senate buildings – was located. As the city expanded going away from that, the buildings became bigger and more technological."
According to Star Trek: Star Charts (pgs. 55, 66), Romulus was located in the Romulus system. The official name of this M-class planet was the Romulan Star Empire, and this world was the capital of the Romulan Star Empire. The planetary capital was named Romulus. The dominant species were the humanoid Romulans. In 2378, the population of this world was estimated to be 18.0 billion. The ancestral homeworld of the colonists, Vulcan, were warp-capable in 320 AD. Approximately fifty years later, these ancestors left Vulcan at the time of the Great Awakening. This planet was located in or near the Romulan War Theater of Operations (2156-2160).
Location of Romulus and the Empire
On screen and in dialogue, the locations of Romulus and the Romulan Star Empire in the galaxy have been exclusively established to be the Alpha Quadrant. It has also been stated that the space of the Romulan Empire was surrounded by the territories of the Cardassians, Klingons and the Federation, all with borders with one another.
The first time this fact began to be established occurred in Star Trek: Deep Space Nine, in the episode "The Search, Part II", where the Romulan Star Empire was identified as one of the great powers of the Alpha Quadrant. For the Dominion, there were four great powers in this quadrant: the Federation, the Klingons, the Romulans and the Cardassians. With the Battle of the Omarion Nebula, two of these threats had been reduced in effectiveness - the Romulans and the Cardassians. By "Call to Arms", the Cardassians were in an alliance with the Dominion and three powers, small and great, had signed non-aggression pacts with the Dominion. These powers were the Miradorns, the Tholians, and the Romulans. In the opinion of Odo, the Dominion was ...making impressive inroads into the Alpha Quadrant.... In "In the Pale Moonlight", it was revealed that the Dominion forces were crossing the Cardassian-Romulan border and were launching attacks against Federation ships from there. The Dominion was secretly planning to invade Romulan space from Cardassia, and, by their estimation, the Romulans would be defeated in three weeks. When Benjamin Sisko was attempting to persuade Senator Vreenak to consider having the Romulans join the offensive against the Dominion, Sisko said "I'd pick the side most likely to leave us in peace when the dust settles. Maybe you're right. Maybe the Dominion will win in the end. Then the Founders will control what we now call Cardassia, the Klingon Empire and the Federation. So, instead of facing three separate opponents with three separate agendas, you'll find yourselves facing the same opponent on every side. There's a word for that. Surrounded".
The association of Romulus with the Alpha Quadrant was carried over to Star Trek: Voyager. In "Flashback", Captain Kathryn Janeway reminisced about what it would be like to live in James T. Kirk's era, with "The Alpha Quadrant still largely unexplored." and "Romulans hiding behind every nebula". In "Message in a Bottle", a border into Romulan space was identified to be located near the edges of Alpha Quadrant. In "Bliss", when it seemed that the USS Voyager would find a way back home, Tom Paris stated that he looked forward to encountering Cardassians, Ferengi and Romulans again in the Alpha Quadrant. In "Flesh and Blood", Chakotay identified the Romulan disruptor as an Alpha Quadrant weapon. In "Q2", in a simulation, several Alpha Quadrant species were fighting over mining rights to a planetoid, and Q Junior had to find a way to settle the dispute. The species listed were the Nausicaans, the Bolians, the Cardassians, the Romulans, the Ferengi, and the Bajorans.
In virtually all reference works however, Romulus and the Romulan Star Empire have been depicted or stated to be located in the Beta Quadrant with a border only with the Federation and the Klingon Empire. These books include such works as the Star Trek Encyclopedia (3rd ed., p 43, 393), Star Trek: Deep Space Nine Technical Manual (page 2), Star Trek: The Next Generation Technical Journal (page 9), Star Trek: The Next Generation Writers' Technical Manual (page 20), Star Trek: Voyager Technical Manual (page 27) and Star Trek: Star Charts (pages 45, 55, 56, etc.). Even reference works that date back to a time before the Alpha and Beta Quadrant distinction was invented depict the Romulans in the area that would later on be classified as Beta Quadrant. These include such works as the Star Trek Star Fleet Technical Manual (T0:02:07:00) and Star Trek Maps (Chart A). Only one of these graphics made a brief on screen appearance as an illegible display graphic on a PADD in Star Trek: Insurrection.   The information on the PADD, though, was completely illegible on screen. 
In some Star Trek novels, Romulus is called ch'Rihan and Remus is ch'Havran. The Romulans are the Rihannsu, and Remus is said to be the more temperate of the two planets. Also, Romulus is said to have at least four moons.
The comic book series Star Trek: Countdown, a tie-in to the 2009 Star Trek film, gives further detail about the destruction of Romulus. The supernova which destroys the planet is identified as being in the Hobus system; Nero and his crew are mining in that system at the time of the star's first eruption. Prior to the destruction of Romulus, Spock attempts to warn the Romulan Senate that the supernova poses a threat to both the planet and the entire Romulan Star Empire, but is rebuffed.