(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 display the awesome beauty of Romulus."
Romulus was an inhabited planet. The planet had at least one moon. This was the homeworld of the Romulans, a warp capable humanoid species. It was the second planet of the Romulan planetary system. This system was located in Sector Z-6, which was a region of space in the Alpha Quadrant. Romulus was the capital of the Romulan Star Empire.
The location of Romulus was depicted on two star charts. In 2266, the location of Romulus was seen on the Sector Z-6 map. (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")
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 the anti-time 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:
Location of Romulus
The common assumption among the fans and some of the production staff was that Romulus was located in the Beta Quadrant. The Romulan Star Empire bordered the Klingon Empire and the United Federation of Planets. This empire didn't border the Cardassian Union. This belief was made canonical with a display graphic from Star Trek: Insurrection that depicted the location of the Romulan Star Empire.  
However, an examination of the dialog painted a different picture. The picture began to be drawn by the series Star Trek: Deep Space Nine. The first time that a location for the Romulan Star Empire was given was in the episode "The Search, Part II". In this episode, 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. 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, the Starfleet officer 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".
This association of Romulus with the Alpha Quadrant was carried over to the sister series, Star Trek: Voyager. In "Flashback", Captain Kathryn Janeway reminisced about what it would be like to live in James T. Kirk's era. In his era, large swaths of the Alpha Quadrant were yet to be explored, and one of the dangers to be encountered in the quadrant was Romulans hiding behind nebula. In "Bliss", when it seemed that the USS Voyager would find a way home to the Alpha Quadrant, Tom Paris stated that he looked forward to Cardassians, Ferengi, and Romulans. 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 conclusion, the Romulans were an Alpha Quadrant species. The territory of their Romulan Star Empire was surrounded by the Cardassians, the Klingons, and the Federation.
Behind the scenes
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."
"The Explored Galaxy"
"The Explored Galaxy" was a map of charted space in the Alpha Quadrant. The chart was also seen in several Star Trek: The Next Generation and Star Trek: Deep Space Nine episodes set in the 24th century, from the year 2364 to 2370. These were TNG: "Conspiracy", "The Measure Of A Man", "The Emissary", "The Mind's Eye", "The Game", and DS9: "In the Hands of the Prophets", "Cardassians".
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).(pgs. 55, 66)
- In some Star Trek novels, the capital city of Romulus is called Ra'tleihfi, and in others as Ki Bataran.
- 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.
- In the video game Star Trek Online, the supernova that destroyed Romulus was intentionally caused by Remans.