Romulan

The Romulans were a humanoid race from the planet Romulus in the Beta Quadrant in the Star Trek Universe. The Romulans were biological cousins of Vulcans, as they were descended from those who rejected Surak's reforms during the Time of Awakening. The Romulan Star Empire was the Romulan state and one of the major powers known in the galaxy. About five thousand years ago the Vulcan planet was primitive, where violence prevailed in all factions, there was a great civil war on the planet until Surak ended the war the fall of a fallen government, initiating a new idealism called IDIC, (Infinite diversity, Infinite combination), founding a high council and an idealistic logic. But a rebel survivor of a war faction called S'task did not agree with Surak's new idealism and his new government in Vulcan, initiating a mutiny, S'task and his eight hundred followers, were expelled from Vulcan on the order of the high council IDIC leaving in three giant ships of few resources, beginning a journey to the new world.

Eighty years passed, the Vulcan ships searched for a new world, they passed many planets. Admiral S'task was recruiting a new security guard from the rear of the ship's migratory fleet, to replace the dead Vulcans officers, aliens such whit the "Sargon", joined the Vulcan crew, Debrune was the Vulcan officer who succeeded in the mission, chosen as future successor of S'task, he used his position and authority to allow small groups of his followers explored several of the planets that the fleet had passed. Unfortunately, most of them lasted only several centuries. Two hundred years passed after S'task's death, Debrune decided to continue the journey to the New World, Three examples of such colonies are Draken IV and Calder II were explored, a war field in Calder II, resulted in the death of 55 crew members, the group descended from the Sargon "vulcanoid", was traumatized after months in the war camp by the Calderians. Commander Debrune divided his remaining followers into two groups and one of the groups gets behind avoiding to continue the journey of the new world, for the loss of their relatives, and decide to stay in a planet class M  these "vulcanoid" groups had already lost all traces of Vulcan, a new species emerged, they decided to separate from the crew and stay on this planet, baptized after of Mintaka III. (ST: TNG - Who Watches the Watchers, season 3). Commander Debrune ordered his route to the new world and let this group continue the journey for themselves, later known as the primitive species Mintakan.

Twenty years later, Admiral Debrune and followers ended up colonizing (in the future neutral zone), the planets Barradas III, Dessica II and Yadalla Prime. Through will power he managed to ensure the survival of the worn crew, but that of Dessica II and Barradas III, flourished. Even now, after 1,000 years, the colony at Yadalla Prime is basically nothing more than a colony of mining and penitentiary (ST: TNG - Gambit part 1 and 2, season 7). Five years after Debrune's death, every Vulcan bond had disappeared by the colonies, his successor, Commander Torak takes possession of the new command and decides to leave behind the colony Debrune, to explore a planet Rigel V. Three hundred years later, the rigelian civilization was at its height, represented by the city of Ancient Grace, which had multi-storey buildings with huge white columns and porticos standing on the hills. But the Rigelians of that time were described as distrustful, possessive, and highly competitive. Originally, Rigel V was home to a "Kaylar population", who became extinct when mixing with the Vulcans, but later became the home of the Rigelians by mingling with the Vulcan immigrants, becoming a vulcanoid race. (Decipher RPG Module: Worlds) The population of Rigel V was known to be rather peaceful. By 2270, it had a population of about 1.2 billion, which had risen to 1.3 billion, around 2365, consisting mainly of Rigelian vulcanoides. (ST Reference: The Federation Worlds) This included 1 billion Rigelians, 200 million Kaylar and Orians trading bases in isolated regions. Subsequently, a plague spread through the population and decimated their numbers, leaving the cities in ruins while native plant life flourished. After the plague had run, the survivors formed a new, more rural, decentralized society with new family units that had many members to prevent them from being so decimated. In addition, their culture has changed to live in the present, instead of focusing on the future or the past. Over the next generations, Rigel V's volcanoes would fight with their own identity as a people, alternating between being known as V'gelnian or the Zami if divided into a segregation between them. The Zami separatist population abandoned Rigel V, and the name Zami, rejecting its system, leaving to the new world with its fleets of ships, and formed a new alliance with the Remans, founding the Romulan empire.

The continuity of the Romulan people was to establish only contacts of technology, one of them was the strong alliance with the Klingons, that after two centuries in commercial disagreements, resulted in a war between them, and the conflict with the birth of the Federation, founding the treaty of the neutral zone. Segregation of the Romulans was divided into two hemispheres of the planet, Romulans with the emblem of v on the forehead is the part of the hemisphere S'hirrikan "Western" and smooth forehead S'hirrikun hemisphere "Eastern", but These two Romulan nations follow the single power of Romulan Empire. The two species Romulans: "S'hirrikan" are descendants of the Zami of Rigel V and "S'hirrikun" are descendants of the Debrune colonies in the neutral zone, with the alliance to the Romulan empire.

In 2150, the Romulans formed an alliance with the Klingons. This alliance resulted in an important technology exchange in which the Romulans gave camouflage technology to the Klingons in exchange for new and advanced starcraft designs. Shortly afterwards, the Romulans were using models of D7 battle cruisers that were able to hide the speed of the fold. This was a major threat to the Federation, which was forced to violate the Neutral Zone and steal a camouflage device to balance the forces. but the commercial disagreements in 2155, ended the Klingon / Romulan alliance entering into a conflict between them, the first was the attack on a Romulan base in Yadalla Prime, both parties leading to chaos, destruction and death.

Due to divergences on the border between the Federation and the Romulan Empire, a war was fought that lasted from 2157 to 2160, when in the Battle of Cheron the Romulans were defeated and elaborated together a peace agreement by subspace radio. The Treaty established the border and established the Neutral Zone between the two territories. The Neutral Zone is a three-dimensional space area of a light year wide that separates the terrestrial space from the Romulan. If someone enters the zone, it is considered as an act of war.

In 2266, the Romulans return to the scene with their new invention, a Romulan Bird of Prey camouflaged with a powerful plasma cannon. They crossed the Neutral Zone and destroyed Federation Outpost 2, 3, 4, and 8. This ship was soon intercepted by the USS Enterprise NCC-1701, which followed it into the Neutral Zone. He fought a tense battle where the USS Enterprise, under the command of Captain James T. Kirk, faced up to defeat the Romulan ship, although its detection by the sensors by the camouflage device is very difficult. Commander Romulan decided to destroy the ship so as not to allow the Federation to acquire camouflage technology, (ST: Balance of Terror, season 1).

When the Klingons opened peace negotiations with the Federation, the Romulans were determined to ensure that their two great enemies would not reach an alliance. The Romulans did not accept the peace talks in Khitomer in 2293, where they conspired against the negotiations with Klingons and members of the Starfleet itself, (Star Trek VI, The Undiscovered Country).

In 2311, the Tomed Incident put an end to diplomatic relations between the Romulan Empire and the Federation. In this incident, thousands of Federation lives were lost by an attack by the Romulans. Almost thereafter, the Algeron Treaty was signed, reaffirming the Neutral Zone, and forbidding the Starfleet to use camouflage technology. The treaty was successful in restoring peace, but in 2344 the Romulans destroyed the USS Enterprise NCC-1701-C, Ambassador class, when it defended a Klingon outpost in Narendra III of a Romulan attack. The ship was under the command of captain Rachel Garrett and its destruction helped to seal the peace between the Klingons and the Federation, (ST: TNG - Yesterdays Enterprise, season 3).

Shortly after in 2345 the Romulans massacred Khitomer (Klingon Planet), killing almost all, leading to a military intervention of the Federation in support of the Klingons that culminated in the signing of the Treaty of Khitomer - A Treaty of peace between the FUP and the Klingon Empire. The USS Intrepid responded to Klingon's call for help in Khitomer, helping some survivors, including little Worf, son of Mogh. Taken over the land was adopted by the Rozhenko family. After these facts the Romulans entered a new period of isolation that lasted until 2364. (ST: TNG - Sins of the Father, season 3)

In 2349 Tasha Yar from a parallel universe was killed while trying to escape from Romulus with her 5-year-old daughter, she was a survivor of a group of 13 crewmembers from the USS Enterprise NCC 1701-C, only 5 survived Romulan executions in service jobs. Tasha Yar was unified to Major B'erak, who spared his life as his wife, in this union had a daughter called Sela, Tasha tried to help to your friend Romulan merchant trying to escape Romulus with his daughter, Sela was agitated without the presence of his father, her cry alerted the security of the place, her act of betrayal to her husband led to the execution, along with the merchant. In 2367, as an adult, Sela is a senior high-ranking commander, Captain Jean Luc Picard meets Sela during the conflict with the Klingons and the existence of another Tasha Yar who was killed in Romulus, Guinan informed Captain Picard of his responsibility to send Tasha to the USS Enterprise-C during the battle at Narendra III with the Romulans. (ST: TNG - Redemption 1 and 2, season 5)

In 2368, after several years of hiding, Ambassador Spock's stay in Romulus was allowed, and authorized by the Romulan Senate, by Senator Pardek, who created a bond of friendship with Spock. Pardek and Spock met at a conference in Kithomer, in their possession as ambassador of the Federation in 2320, but their friendship ended because of Pardek's betrayal of attempting to destroy Romulans' reunification with the Vulcans. (ST: TNG - Unification 1 and 2, season 5).

From 2370, with the destruction of Romulan posts and the Federation by the Borg, the Romulans left the isolation and became more participant and active. The Borg threat caused Romulan forces to begin developing new weapons and many were tested in raids against the Federation and the Klingons (ST - Voyager: Unity, season 3).

In 2374, the Romulans signed the "union Treaty" with Klingon / Federation against the Dominion when the War against the Dominion began, from the Dominion threat to the Romulan empire, killing about 5 Praetors and 3 important Senators, creating the task force representing a great danger to the Dominion, forming the so-called Triple Alliance Federation / Klingons / Romulans that led the Dominion to surrender in the five years of war. (ST: DS9 - In the Pale Moonlight, season 6).

In 2379, the new Praetor Shinzon comes into power Reman to try to take possession of the Romulan empire, summoning the Senate to threaten the destructive radiation of Thalaron in exchange for a large fleet of Romulans ships invading and destroying the earth with radiation, but the Senate disapproved, resulting in the death of all of them because of Senator Tal'aura's betrayal, by receiving a positronic signal from the Remans by the Scimitar ship in the neutral zone, USS Enterprise NCC 1701-E is damaged, and Scimitar is destroyed by the Thalaron radiation explosion, Data is destroyed by saving the Enterprise crew killing shinzon, after months in repair at Shipyard 7, the Enterprise returns to space, returning the wreckage, rescuing the Data's head, Engineer Gerogi La Forge, crosses Data neural network to his twin brother B-4, restoring the Data system to his brother's body, the Enterprise heads to Starbase 23, for the inauguration ceremony of the new Captain of Enterprise, Captain Data, and withdrawal of command service of Jean Luc Picard, for services to the San Francisco Starfleet. (Star Trek - Nemesis) About two thousand and a half years, after the founding of the Romulan empire in 2387, The great Romulan sun "Hobus" enters in a Supernova, because of the red matter, the attempts to save Romulus by Ambassador Spock was unsuccessful, he disappeared in the vacuum of energy, before the formation of Supernova, caused the destruction of the Romulan system, destroying the entire system, including Romulus and Remus, only 252 Romulan ships and 78 Remans ships sheltering the survivors who were on an exploration mission. The USS Titan NCC 80102, under the command of Captain William Riker, who was in the peace agreement mission with the Romulans, requested the help of the new Captain of the USS Enterprise NCC 1701-E, Captain Data, to assist in the orientation of opening colonies to these survivors in Romulak III, a trading planet of the paradisiacal Romulans in the neutral zone, the Remans colonized Hermeticus V. With the support of the Federation, this aid helped to consolidate the annulment of the treaty of the neutral zone in 2399, and the Romulans became part of the Federation. With the disappearance of ambassador Spock, being given as dead, Saavik succeeded Spock like ambassador of Romulak III, Data discovers by ambassador Saavik that the commander Sela (daughter of Tasha Yar) died in the destruction of Romulus. Romulak III, the third and last planet of a yellow dwarf star "C'yton", smaller than Hobus, is composed of a moon called Zeta, this moon has important minerals, for the development of the planet, discovered by the Remans in 2355, the Romulans built two bases on this moon.

Ancient origins
Commander Spock once theorized that Sargon's people may have colonized Vulcan some six million years ago. Sargon believed that Humans and Vulcans (and therefore also Romulans) might even be descendants of their early travelers. (TOS: "Return to Tomorrow")

With the discovery of ancient humanoid progenitors in the 24th century, most humanoid life forms in the known galaxy were found to have a "seed" genetic code guiding their evolution to the humanoid form. (TNG: "The Chase")

Modern origins
When Surak's reforms of embracing logical principles and rejecting emotions spread rapidly across Vulcan in the 4th century, a minority rejected Surak's ideals. They departed Vulcan in the 4th century; later, some of their descendants established settlements on the planets Calder II, Dessica II, Draken IV, Yadalla Prime and Barradas III. An ancient offshoot civilization, called the Debrune, at one time existed on Barradas III but it had died out by the 24th century. (TNG: "Gambit, Part I")

At some point, another group settled on twin planets that became known as Romulus and Remus. While Romulus was a Class M planet, Remus was a harsh planet notable only for its dilithium deposits. These two worlds were the foundation of an interstellar empire that expanded to many worlds, reaching across some of the Beta Quadrant. Eventually that power came to be known as the Romulan Star Empire. (TNG: "Gambit, Part I", "Gambit, Part II"; Star Trek Nemesis)

In 2387, a star close to Romulus went supernova. Although Ambassador Spock attempted to prevent the supernova from striking the planet, he was ultimately unsuccessful and Romulus was destroyed. (Star Trek)

Mirror universe
In the mirror universe, the Romulans appeared to be uninvolved in the conflict between the Terran Rebellion and the Klingon-Cardassian Alliance.

Prime Benjamin Sisko, posing as mirror Benjamin Sisko, indicated to Jennifer Sisko that he was going to visit the Romulans to see if he could get their support. This was, in reality, a ruse to explain his return to Deep Space 9. (DS9: "Through the Looking Glass")

First contact
Romulans were aware of Humanity for some time before Earth knew of them. Infiltrating the highest levels of the Vulcan High Command, the Romulans were impressed and confused by Humans. The Enterprise NX-01 inadvertently encountered a Romulan minefield at one point, drawing even more Romulan attention. Even after fighting the Earth-Romulan War, it wasn't until the 23rd century that Humans saw them. (ENT: "Minefield"; TOS: "Balance of Terror")

After the Treaty of Algeron went into effect, the Romulans retreated into political and social isolation from the Federation. In late 2364 an unprovoked attack on a Romulan outpost near the Federation Neutral zone occurred. The Romulans initially suspected the Federation had executed the attack but it was later learned that the Borg were responsible. This event marked the end of Romulan political isolationism with the Federation. (TNG: "The Neutral Zone")

Relationships with other species
In keeping with their xenophobic and arguably racist attitudes, the Romulans tend to conquer species rather than form alliances with them, and individual Romulans tend to treat other species with varying degrees of disdain.

That did not prevent them from employing diplomacy when it suited their purposes. Soon after their emergence from a century of isolation in the mid 2260s, they had established at least two embassies with the Federation. One such embassy was a three-way endeavor on the planet Nimbus III, along with the Klingon Empire, and the other was on Earth itself. (Star Trek V: The Final Frontier, Star Trek VI: The Undiscovered Country)

Klingons and Romulans once shared an alliance for a number of years, beginning in the 2260s. Over the years, a number of incidents, including the Khitomer Massacre, led the Klingons to develop a deep seated hatred for the Romulans, and the Romulans were arguably the species that Klingon society in general despises most of all. (TOS: "The Enterprise Incident"; TNG: "The Neutral Zone")

A Cardassian embassy existed on Romulus for a time, and Elim Garak was "employed" there as a "gardener," suggesting that the two species maintained an active diplomatic relationship. (DS9: "Broken Link") In 2371 Romulan and Cardassian agents in the Tal Shiar and the Obsidian Order cooperated in an attempted attack on the Dominion. (DS9: "Improbable Cause", "The Die is Cast") The Romulans had certainly cut ties with the Cardassians by the time they entered in to the Dominion War, but when their relationship ended prior to this was unclear.

One common saying among the Romulans was "Never turn your back on a Breen." While this statement could be taken as partially humorous and not in itself indicative of hostilities between the two species, the Breen Thot's apparent condition that the Breen be given Romulus in exchange for their help in the Dominion War suggested there was some degree of unfriendly history between the two. (DS9: "By Inferno's Light", "Strange Bedfellows")

The species that Romulans seem to dislike most, however, were Vulcans, and this feud goes back many centuries. The two powers once fought in a war that lasted 100 years, that was ignited due to a misunderstanding created by one of Q's self-destructive stunts. (VOY: "Death Wish")

The two species would remain distrustful of one another for an incredibly long time, but some Romulans grew tired of this, and a grassroots movement for reunification of the two species was active for a time on Romulus. It was generally assumed that after the split, Romulans and Vulcans were unaware of their common ancestry until the 23rd century. (ENT: "Kir'Shara"; TOS: "Balance of Terror")

Biology
Due to their shared ancestry, Vulcans and Romulans possess very similar anatomy and physiology. Romulans have pointed ears, eyebrows that are arched and upswept, and copper-based blood that appears green when oxygenated in the arteries, or copper or rust-colored when deoxygenated in the veins. (Star Trek Generations) Most Romulans have two brow ridges above the bridge of their nose, forming a V-shape on the forehead. However, a minority of Romulans lack these ridges, making them outwardly indistinguishable from Vulcans.

Despite their common ancestry there are also many subtle internal physiological differences between Vulcans and Romulans. This is evidenced in Dr. Beverly Crusher's failed attempt to treat a Romulan, Patahk, who had suffered advanced synaptic breakdown, with the methods used to treat Vulcans. In fact, it was later determined that the genetic similarities between Romulans and Klingons allowed for the two species to have a compatible ribosome match to effect treatment. (TNG: "The Enemy")

The Terothka virus was a disease unique to Romulan physiology. Romulans were also susceptible to Tuvan Syndrome. (VOY: "Message in a Bottle"; DS9: "Inter Arma Enim Silent Leges")

There were numerous instances of Romulans successfully mating with other species, as evidenced in Sela (Romulan/Human), Ba'el (Romulan/Klingon), and the grandfather of Simon Tarses (Romulan/Human).

Romulans lacked the rigorous mental disciplines developed by the followers of Surak. They were a passionate people, easily moved to extreme emotions. (TOS: "The Enterprise Incident")

However, like their biological cousins, Romulans possessed greater physical strength than that of a Human. (Star Trek: The Motion Picture)

Society
In Romulan society, military/political rank influences social standing. Because Romulans were members of a militant civilization, who considered defending the Romulan Empire and their own personal honor of foremost importance, military service and its accompanying rank were decisive factors in determining social eminence. (TOS: "Balance of Terror") However, while the military played an important role in Romulan society, it was the Romulan Senate that controls the government. (Star Trek Nemesis)

At one point in history, Romulus was a sovereign nation ruled by an Empress, as indicated by Q. (VOY: "The Q and the Grey") By the 23rd century the highest position of power was held by the Praetor, who presided over the Romulan Senate. (TOS: "Balance of Terror"; Star Trek Nemesis) The Praetor headed the Continuing Committee, which was comprised of the Empire's most elite individuals, which make decisions of the utmost importance. (DS9: "Inter Arma Enim Silent Leges")

By the 24th century, the government of Romulus was dependent upon the Tal Shiar, the Romulan secret police, to maintain order and stability among both civilians and the military. The Tal Shiar was known for its brutal tactics, which included routine kidnapping, torture, and assassination. Many Romulans fear even expressing dissenting opinions as not to spark the interest of the Tal Shiar. There was also indications that tension existed between the military and the Tal Shiar. (TNG: "Face of the Enemy")

Romulan society was based upon a highly structured caste system. Unlike most of the highly evolved species in the Alpha and Beta quadrants, Romulans still practiced slavery, specifically the Remans, which they used for slave labor and as shock troops. (Star Trek Nemesis)

Romulans tended to be highly xenophobic, engaging in extended periods of isolationism, and could be perceived as outright racist to other species, believing themselves to be superior. At least some Romulans believe that one day the Romulan Empire will rule the entire galaxy. (TNG: "The Neutral Zone", "Data's Day", "The Enemy") According to Miles O'Brien, there was no piece of technology in existence that the Romulans didn't claim they invented before everyone else. (DS9: "Explorers")

Romulan society did not appear to have gender biases. Both males and females commanded warships, could obtain high political positions and could be members of the Tal Shiar. (TOS: "The Enterprise Incident"; TNG: "Contagion"; TNG: "Face of the Enemy"; DS9: "Image in the Sand")

Culture and tradition
"Paranoia is a way of life for you, isn't it?"

- The Doctor to Rekar (VOY: "Message in a Bottle")

The Romulans lack the rigorous mental disciplines developed by the followers of Surak. Like the Vulcans, the Romulans have given up unrestrained violence as a way of life. However, in the case of the Romulans this has been replaced with a controlled deviousness: As a species the Romulans were generally thought of as duplicitous, a reputation the actions of their government over the last decade has reinforced. (TNG: "The Neutral Zone")

During the 23rd century, Romulans practiced the execution of state criminals, by means both painful and unpleasant. Prior to the presenting of the charges, the Romulans allow the accused a Right of Statement. (TOS: "The Enterprise Incident")

Reluctance to rely on overt hostility generally lead the Romulans to play a waiting game with their opponents, attempting to manipulate an adversary into breaking – or appearing to break – an agreement so as to give them a solid justification for striking. (TNG: "The Defector", "The Pegasus")

They were also well known for fearing disgrace over death. (TAS: "The Practical Joker") With this frame of mind, Romulan parents dispose of any newborn carrying birth defects as the alternative would mean a waste of resources. (TNG: "The Enemy")

The totalitarian nature of Romulan society, in which dissent was often a crime and Romulan security officers masquerade as citizens, had led many Romulans to be extremely paranoid. (TNG: "Unification I")

A common Romulan courtesy was the saying "Jolan Tru", although what exactly this means is unclear, as it is used both in context of greeting and goodbye. (ENT: "United"; TNG: "Unification I", "Unification II")

In the 24th century, a dissident movement began to gain momentum, based on the desire to learn about Vulcan and Vulcan ideals. Their ultimate goal was the reunification of Romulus and Vulcan. Ambassador Spock was deeply involved in this movement. (TNG: "Unification I", "Face of the Enemy")

While many arguably belligerent and militaristic species, such as Nausicaans, Breen, and even Klingons often sell their fighting skills to the highest bidder, Romulans were rarely, if ever, seen involved in such activities. This was possibly due to the apparent superiority complex of most Romulans, many of whom would likely find such work beneath them, and would prefer to serve the Romulan Empire in some capacity. However, Miles O'Brien once played a game of Tongo with a Romulan mercenary. (DS9: "Change of Heart") In cases of anonymity, they were known for commonly using hired assassins, such as the Flaxians, to conduct their off-world "justice." (DS9: "Improbable Cause")

Food and beverages

 * Kali-fal
 * Jumbo Romulan mollusk
 * Osol twist
 * Romulan ale
 * Viinerine

Background
The Romulans were created by writer Paul Schneider and introduced in "Balance of Terror". He modelled them on the Romans, naming their planets after the mythical founders of Rome Romulus and Remus. The Romulans next appeared in "The Deadly Years" via recycled footage of the Romulan Bird-of-Prey, before making a physical reappearance in "The Enterprise Incident".

Saavik was intended to be half-Vulcan, half-Romulan. The Romulans were meant to be the villains in Star Trek III: The Search for Spock, but director Leonard Nimoy preferred the more "theatrical" Klingons. The Klingon Bird-of-Prey was meant to be stolen from the Romulans, but this information was left out of the film. The Romulans finally reappeared in the Star Trek: The Next Generation episode "The Neutral Zone", where makeup artist Michael Westmore gave them 'V'-shaped forehead ridges to "compete" with the Klingon redesign introduced in Star Trek: The Motion Picture. (The Art of Star Trek)

The Romulans would've had a grander future had the animated series Star Trek: Final Frontier been produced instead of Star Trek: set in the 2460s, a war caused by Omega particle detonations (which was not actually the Romulans' fault) permitted them to conquer Qo'noS, destroy Andoria, and forced the Vulcans to leave the Federation to negotiate reunification. The Earth-Romulan War was also intended to be explored in the fifth season of Star Trek: Enterprise and the film Star Trek: The Beginning, neither of which were produced. Brannon Braga and Manny Coto considered making "Future Guy" a Romulan and revealing T'Pol's father was a Romulan agent.

Apocrypha
Diane Duane created her own take on the Romulans in her novels, in which she reveals their true name to be the Rihannsu. Duane also depicted the Romulans as being extinct in the mirror universe novel Dark Mirror, as they chose to commit mass suicide rather than become subjects of the Terran Empire following the Battle of Cheron.

Much of the Romulans' origins are explored in the Vulcan's Soul trilogy. In them, the Romulans' ancestors left Vulcan as a contingency plan approved by Surak, should the wars on Vulcan have completely destroyed their civilization. It is stated the Romulans rejected the telepathy of the Vulcans and slaughtered or enslaved the telepathic ones among them during their exodus to the Romulan system: the telepaths became the Remans. This explains why no Romulan displays telepathic skills in canon. The eagle emblem was inspired by a huge bird native to Romulus that clutched eggs in its talons.

Romulan religious beliefs vary in non-canon sources. The Way of D'era sourcebook states the Romulans believe in the Way of D'era. Tellus, an enemy of Surak, taught that the inhabitants of Vorta Vor – the mythological world mentioned in Star Trek V: The Final Frontier – had visited the Vulcans and inspired them to become the supreme rulers of the galaxy. This explains the superiority complex and their hatred for Vulcans, whom they see as traitors. In Duane's My Enemy, My Ally, it is said the Romulans worship the classical elements of fire, air, water, earth and the "Archelement" which oversees the others. In Killing Time, they worship a demon called Bettatan'ru.

The Way of D'era adds that the Romulans lack the physical strength of the Vulcans because they no longer live on a harsh environment. Killing Time shows Romulans slightly adverse to the effects of pon farr.

The comic book Star Trek: Countdown and the video game Star Trek Online depicts the lead up and the aftermath of Romulus' destruction, primarily caused by the Romulan Senate ignoring Spock's warnings about the supernova, and the Vulcan Science Council's refusal to lend them red matter. In spite of this, Federation-Romulan relations had been improving and Romulan citizens had become less xenophobic, as indicated in the ending of Star Trek Nemesis. After the supernova, Federation aid is either welcomed or met with suspicion and even hostility, while the Klingon Empire seizes the opportunity to conquer Romulan territory. Despite continuing in-fighting between the survivors, a new capital called Rihan is established on Rator III.

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