Human - Romulan history Human - Romulan history was mostly a series of confrontations between United Earth , and later the United Federation of Planets , and the Romulan Star Empire that once brought the two powers to an all out war . This was sometimes referred to as a game of chess and brinkmanship . ( ) Return from Isolation . After 53 years of isolation following the Tomed Incident , which had been resolved by the Treaty of Algeron , a buildup of seven Romulan battle cruisers were detected on approach to a Federation Neutral Zone outpost . The outpost requested reinforcements and the and responded . The arrival of the two Federation starships was a critical show of force that deterred the Romulans from taking any offensive action . ( ) Later that year , several Federation outposts along the Romulan Neutral Zone suddenly disappeared . Starfleet ordered the " Enterprise " - D to investigate . The " Enterprise " encountered a Romulan Warbird that had been investigating the disappearance of their own outposts along the Neutral Zone . After a tense standoff , both crews were able to determine that neither side was responsible for the attacks against the other . Nevertheless , the Romulans were unhappy with what they considered rapid expansion of the Federation while they remained in isolation during the last few decades . They promised they would no longer be " negligent " in this affair . ( ) Search for the Iconian Gateway . When Captain Donald Varley of the received word of a possible Iconian gateway in the Neutral Zone , he felt it necessary to risk war by taking the " Yamato " into the Zone . The gateway would have allowed the Romulans to move legions of troops across star systems without the use of starships or conventional transporters . Varley felt it could not be allowed to fall into Romulan hands at any cost . The " Yamato " was destroyed when an Iconian computer virus caused a malfunction of the ship ' s antimatter containment system . As the " Enterprise " continued the investigation , it was confronted by the Romulan Warbird " Haakona " . The " Haakona " ordered the " Enterprise " to withdraw , but the " Enterprise " refused , stating they would not withdraw until they had determined the cause of the destruction of the " Yamato " . The " Enterprise " later located the Iconian gateway deeper within the Neutral Zone and destroyed it . ( ) Galorndon Core Incident . A Romulan scout ship crashed on the Federation planet Galorndon Core near the Romulan Neutral Zone . The USS " Enterprise " - D found one survivor and brought him on board . However the Federation vessel was ill - equipped to treat the gravely wounded Romulan soldier . A Romulan Warbird raced across the Neutral Zone to rescue the injured Romulan , however they were warned by the " Enterprise " that any Romulan ship that entered Federation space would be fired upon . Therefore , the Romulans demanded that the " Enterprise " rendezvous at the border so they can treat their injured soldier . The " Enterprise " was unwilling to leave as it had one of its own crewman trapped on the planet due to intense storms interfering with transporter activity . As a result , the Romulan later died of his injuries on the " Enterprise " . The Romulan commander was outraged and threatened to destroy the " Enterprise " in retaliation . Both vessels diverted powered to their weapons systems and locked on to each other . However , the " Enterprise " detected another Romulan survivor during a break in one of the storms . Captain Jean - Luc Picard offered to lower his shields to beam the Romulan survivor and the trapped " Enterprise " crewman on board . He reminded the Romulan that if the " Enterprise " was destroyed , so too would the peace between their two peoples . In the end , the Romulan commander did not fire and the second Romulan survivor was returned to his custody . ( ) Nelvana III Incident . A Romulan scout ship raced across the Neutral Zone while under close pursuit by a Romulan Warbird . When confronted by the USS " Enterprise " - D , the Warbird withdrew . The scout ship carried a Romulan soldier claiming to be a defector . He warned of an imminent Romulan attack from a hidden military base on Nelvana III inside the Neutral Zone . He claimed that the base would be operation within 48 hours and a fleet of Romulan Warbirds would be in striking range of fifteen Federation sectors . Starfleet Command ordered the and to head towards the " Enterprise ' s " location , but they would not arrive before the 48 hour deadline . Captain Picard also requested reinforcements from the Klingon Defense Force . The " Enterprise " decided to launch a preemptive strike and destroy the base before it became operational . However , there was no base at Nelvana III . When the " Enterprise " arrived , two Romulan Warbirds had been lying in wait and ambushed the vessel . The Romulan commander demanded the " Enterprise " ' s surrender . Captain Picard refused and signaled three Klingon warships to reveal themselves . The Klingon ships , which had followed the " Enterprise " under cloak , disengaged their cloaking devices and surrounded the Romulan ships . The Romulan commander decided to withdraw , narrowly averting a war once again . ( ) Ambassador T ' Pel incident . The USS " Enterprise " - D was ordered to take Federation Ambassador T ' Pel to the Romulan Neutral Zone to discuss the establishment of full diplomatic relations . However , as the ambassador attempted to beam aboard a Romulan Warbird to begin discussions , a transporter malfunction apparently killed her . Both ships returned to their respective territories . An investigation later determined that the accident had been faked and T ' Pel was still on board the Romulan ship . The " Enterprise " immediately raced back to the Neutral Zone and confronted the Romulan ship . They armed their weapons systems and demanded that the Romulans return Ambassador T ' Pel at once . Another Warbird decloaked , but the " Enterprise " refused to leave without the ambassador . The Romulan commander stated that he was not prepared to start a war that day and revealed to the " Enterprise " that T ' Pel was in fact a Romulan intelligence operative . Since it was apparent that the Romulans were no longer holding a Federation citizen hostage , the " Enterprise " returned to Federation space without further incident . ( ) Krios incident . In 2367 , the Romulans attempted to destroy the Federation - Klingon alliance by arming pro - independence rebels on the Klingon - held planet Krios Prime with fabricated Starfleet phaser rifle s . In addition , Romulan agents kidnapped and brainwashed Lieutenant Commander Geordi La Forge into attempting to assassinate Governor Vagh . The Romulans hoped , unsuccessfully , to incite the Klingon s into going to war by framing the Federation . ( ) Klingon Civil War . In 2368 , the Romulans increased their clandestine efforts to influence Klingon politics , and thereby break the Federation - Klingon alliance , by directly supporting the House of Duras in the Klingon Civil War . Suspecting Romulan involvement , the Federation established a twenty - three ship blockade along the Klingon - Romulan border using a tachyon detection grid . The Federation obtained proof of Romulan involvement when several cloaked warbird s attempted to evade and cross the blockade . Having been discovered , the Romulans quickly withdrew their support from the Duras , ending the war . ( ) Reunification attempt . Several stolen Vulcan ships were used by the Romulan military to transport ground troops in an attempted invasion of Vulcan . They posed as members of Ambassador Spock ' s Vulcan - Romulan reunification movement . Spock himself discovered the plan and warned Federation authorities . Vulcan defense forces were mobilized and the USS " Enterprise " - D intercepted the invasion force in the Neutral Zone . The Romulans , unwilling to let their ground forces be captured by Starfleet , destroyed their own invasion force , killing two thousand of their own soldiers . ( ) Despite the Romulan military ' s attempt to usurp their movement , the Romulan underground nevertheless continued to advocate for reunification and facilitated the defection of Vice - proconsul M ' ret to the Federation . ( ; ) Development of interphase and phasing cloaking technology . In 2368 , the USS " Enterprise " - D responded to a distress call sent by a Romulan science vessel with an apparently damaged graviton generator and a warp core breach in progress . In reality , the Romulan ship had been conducting secret experiments to develop an interphase cloaking device using a molecular phase inverter . To eliminate all possible Federation knowledge of the experiments , after accepting help from the " Enterprise " to resolve the core breach , the Romulan crew planned to surreptitiously generate a muon wave directed at the " Enterprise " dilithium crystal chamber , which would cause a catastrophic explosion the moment the " Enterprise " engaged warp drive . This threat was discovered and eliminated by Lieutenant Commander Geordi La Forge and Ensign Ro Laren . ( ) In 2370 , both Starfleet and the Romulans attempted to find and salvage the derelict , which was previously thought to have been destroyed in 2358 . The intense renewed interest in the ship was due to the fact that the " Pegasus " carried a prototype Federation phasing cloaking device , developed in violation of the Treaty of Algeron , by which the Federation had pledged not to develop cloaking technology . Existence of the phasing cloak was acknowledged by the Federation to the Romulans when the device was briefly installed and used on the USS " Enterprise " - D . According to Captain Jean - Luc Picard , the scandal would likely result in courts martial prosecutions against senior officers of Starfleet Intelligence . ( ) Devron system anomaly . In one alternate timeline , a disruption of anti - time created a temporal anomaly in the Devron system , located in the Neutral Zone . Thirty Romulan Warbirds were sent to the border as well as fifteen Federation starships , including the USS " Enterprise " - D , the , and the . ( ) USS " Prometheus " incident . The Romulans learned of the top secret prototype and sent troops to capture the vessel . The Starfleet crew was killed and the Romulans took the ship on a heading for Romulan territory . The intercepted the " Prometheus " but was quickly disable in an exchange of fire . Three additional Federation starships intercepted the " Prometheus " in the Romulan Neutral Zone , where they were engaged by three Romulan Warbirds . The EMH mark II program on the " Prometheus " with the assistance of another fellow EMH managed to retake control of his ship and destroyed one of the Romulan Warbirds . The remaining two Romulan ships withdrew shortly thereafter . ( ) Uniting against the Dominion . In recognition of the need to jointly gather intelligence in the face of a threatened Dominion invasion of the Alpha Quadrant , in 2371 the Romulans consented to installing a cloaking device aboard the . ( ) Although later that year the Romulan Tal Shiar and the Cardassian Obsidian Order jointly launched an unsactioned , and ultimately disastrous , preemptive strike against the Dominion , the Romulan government officially remained neutral in the Dominion War until 2374 . ( ) Unknown to the Romulans , the Federation successfully framed the Dominion for the assassination of Senator Vreenak , thereby causing the Romulans to enter the war on the side of the Federation and the Klingons . ( ) Relations during the war improve to the point where a joint Federation - Romulan medical conference was convened on Romulus , although below the surface the Federation ' s secret Section 31 worked to turn Tal Shiar chairman Koval into a double agent . ( ) Battle of the Bassen Rift . Section 31 had predicted that at the end of the Dominion War , the only two remaining powers that could vie for control of the Alpha Quadrant were the Federation and the Romulans . ( ) . Once the war had ended , the Romulan military pushed for an invasion but the Romulan Senate refused . The new Reman leader Shinzon pledged to destroy the Federation should he become the next Praetor . With the assistance of the Romulan military , the Senate was overthrown in a " coup d ' etat " , and Shinzon was made the new Praetor of the Romulan Star Empire . Shinzon was in command of the Reman Warbird " Scimitar " - a heavily armed warship that had both conventional and biogenic weapons . The was to lure the " Scimitar " to sector 1045 where a Federation fleet was lying in wait to attack the Scimitar . Instead the " Scimitar " chose to ambush the " Enterprise " first , inside the Bassen Rift where communications with Starfleet was not possible due to interference . After an exchange of fire between the " Enterprise " and the " Scimitar " , the Romulan military decided they would no longer support Shinzon . The military was only interest in the conquest of Earth , not mass genocide through the use of biogenic weapons . Two Romulan Warbirds arrived to assist the " Enterprise " . Both the " Enterprise " and the two Romulan ships were badly damaged in the ensuing battle , however the Scimitar was destroyed in the end . ( ) Destruction of Romulus . The cold war reached an eventual end in 2387 with the destruction of Romulus by a supernova , despite Spock ' s attempt to prevent the catastrophe . ( )