The species origins were traced to the planet Agornu where the Gorn were noted for being both a very old and a highly sophisticated civilization. Thousands of years ago, the first empires arose following the discovery of agriculture which eventually formed the first Gorn states. Over the next few centuries, the barbarism of Agornu was conquered by the Gorn people who absorbed such regions to form an empire. In the time that followed, the Gorn began colonizing nearby worlds which were later united into a single great empire after the invention of the warp drive. (TOS module: Star Trek: The Original Series Core Game Book)
The Gorn race was actually three species who were genetically identical and lived on three separate worlds. After they achieved space travel, the three Gorn races discovered one another and learnt of their similarity whereupon it was discovered, through fossil records, that none of their planets was their race's true homeworld. Seeing the similarity, the three races joined one another into a single political unit. (TOS video game: Starfleet Command II)
The Gorn had achieved interstellar propulsion technology as far back as 500,000 BC when they established a cemetery world on the planet Cenotaph. They marked this world by placing numerous kilometer wide stone spheres in equatorial orbit which were engraved with a warning that anyone who trespassed would be committing a grave sacrilege. (TOS comic: "Dying of the Light")
Early in their history, the Gorn people encountered the Paravian species. The encounter led to hostilities between both races and eventually to the extermination of the Paravian people by the Gorn's hand. The next species they encountered was the Romulan Star Empire. Because the Romulans lived in a poor region of space, the Gorn Hegemony and the Romulan Star Empire battled in a war for resources over the few planets they managed to discover. The Gorn achieve several victories but each were costly and bloody. This resulted in a constant state of conflict between the two races. Both set of hostile encounters clouded the Gorn’s view on other races. (TOS video game: Starfleet Command II)
The Gorn made first contact with the Federation in 2267 when a Gorn vessel attacked a Human colony on Cestus III interpreting the colonization as in invasion into Gorn Space. The vessel was pursued by the USS Enterprise until the Metrons, a non-corporeal species, intervened and forced the commanders of both ships to battle to death for control of Cestus. Kirk of the Enterprise won, but refused to kill the Gorn commander. (TOS episode: "Arena")
The following year a Human archaeologist, Holm Baynan, traveled to the Gorn cemetery world Cenotaph to conduct research. Aware the Gorn would pursue him for pillaging their sacred world he issued a fake distress call to bring the Enterprise to the planet so that he could quickly have them take on the artifacts he discovered and make his escape. Unfortunately a trio of Gorn cruisers arrived before the Enterprise departed, demanding the ship surrender to take a quick death for their crimes. Fortunately for the Starfleet crew the lead Gorn vessel was commanded by S'slee, the same Gorn Kirk had battled before, the familiarity between the commanders, coupled with the token destruction of one of the Enterprise's shuttles by Kirk, allowed the situation to calm from conflict to a cultural exchange. (TOS comic: "Dying of the Light")
In 2282, a Federation shuttlecraft crashed on a planetoid used by the Gorn to train young warriors. A Gorn rescue party was sent to aid the survivors, who mistook them for a war party and shot their physician, Thak. The Gorn, surprised and infuriated by the unprovoked attack, prepared to retaliate, but the Humans, having realized their mistake, treated Thak's wounds, enabling him to explain the situation to his people. (TOS comic: "Alien Spotlight: The Gorn")
In the 2280s, the Gorn Hegemony was ruled by a king who was old and lacked authority. Actual running of the government was left to the King's advisors and children. Though the government suffered political problems, it was still quite a powerful military force that was more then enough to challenge other governments near their territory. (TOS video game: Klingon Academy)
The Romulans were noted in attempting to fracture the newly developed Gorn-Federation alliance, however, their attempts only served to further cement the two's relations which became based on mutual trust as well as respect. (TOS video game: Starfleet Command II)
In 2370, there was growing unrest within the Gorn empire with a more militant faction seeking to undermine the dominant government and declare war against the Federation. Peace talks were made through the efforts of Captain Jean-Luc Picard who attend the Gorn Summit that managed to aver the crisis. (TNG novel: Requiem)
- Considering the fact that Gorn Crisis comes into the future, the elements within the Gorn government that were seeking to declare war may very well have been the Black Crest.
In 2374, after decades of peaceful relations with the Federation, the Gorn government was toppled by a coup d'etat by the Black Crest faction, and a new offensive was launched against Cestus III. A halt to these hostilities was negotiated by the crew of the USS Enterprise-E, who also managed to persuade the Gorn to join the Federation Alliance in the war against the Dominion. (TNG comic: "The Gorn Crisis")
Thanks to their familiarity with the Gorn, the Enterprise crew were later able to convince the Gorn to join a task force to meet the 'Iconians' in the gateways crisis of 2376. (TNG novel: Doors Into Chaos)
By 2379, the Gorn Hegemony had established normal diplomatic relations with the Federation, and even maintained a diplomatic mission on Earth. The Gorn Ambassador to the United Federation of Planets that year was Zogozin, whom Federation President Min Zife of Bolarus found very intimidating. (TNG novel: A Time to Heal)
On Stardate 61829.83 in 2384 a Gorn starship attacked the IKS Quv in international space. 207 Klingons were killed and King Xrathis refused to hand over the survivors. Chancellor Martok retaliated by expelling Gorn diplomats, and dispatched Klingon Defense Force vessels to their common border.
Xrathis died in 2386 and was succeeded by his son Crown Prince Slathis. He reinforced the Gorn side of the border, and several KDF-Gorn skirmishes followed. Full-scale war broke out on Stardate 63504.74 of that year when the Klingons attacked the Gorn colony at Gila IV, capturing it after a two-day battle. The Federation then intervened to mediate between the two powers, and negotiations dragged out for the next three years.
In 2389 the war resumed with the battle for the Gamma Orionis system. Slathis negotiated a deal with Nausicaan mercenaries, granting them rights to several asteroid belts and a substantial payment in exchange for joining the war on their side. Despite this, the Klingons held onto Gamma Orionis.
Starfleet agreed to Martok's demand in 2391 and dispatched ships to battle the Nausicaans in exchange for Martok committing to peace talks. Representatives of the Klingons, Gorn, and Nausicaans met at Deep Space K-7, but talks collapsed two days in when Gorn Ambassador Zogozin was injured by a bomb. Starfleet Security investigated and linked J'dah, a Klingon extremist, to the attack, but he was killed by an unknown attacker before he could be arrested.
The Klingons advanced into Gorn territory, and Slathis recalled forces from the outlying colonies to protect Gornar. He attempted to gain the assistance of Lethean mercenaries, but outside analysts doubted he had the resources to pay both them and the Nausicaans.
In 2392 another round of peace talks began on Cestus III, but the preliminary talks came to no conclusion. On Stardate 69259.56 a Gorn-Nausicaan fleet attacked the Klingon planet Ogat, but were repelled after a two-week battle.
Chancellor J'mpok, who had slain Martok in an honor duel in 2393, reluctantly agreed to yet another round of talks in 2397. On Stardate 75705.90, the peace conference on Casperia Prime was bombed by a Klingon extremist group. The Federation tried to restart the talks but the Klingons and Gorn withdrew their delegations.
In 2399 Captain Ja'rod, son of Torg of the IKS Kang returned to Qo'noS with evidence that the Gorn had been heavily infiltrated by Species 8472. The next day Chancellor J'mpok ordered a full-scale invasion of the Hegemony, and within weeks a Klingon-Orion fleet stormed the border. Gorn and Nausicaan ships fought bravely against the invaders through 2400, earning the Klingons' respect with their ferocity. The Federation Council declared the war unlawful but was ignored.
In 2402 the Klingons reached Gornar and laid siege to the planet. The Gorn attempted to prevent an invasion by erecting a network of transporter scramblers and laying a minefield of cloaked self-replicating mines to prevent a shuttle landing. However, on Stardate 80344.81 (2403) the transporter scramblers failed and the Klingons made planetfall, heading straight for the capital city. Twenty-eight hours after the invasion began, KDF ground forces stormed the royal palace. King Slathis surrendered to General Klag, son of M'Raq, who agreed to lift martial law orders against the civilian population. The Klingon occupying force were noted for remarkable civility towards Gornar's civilians.
Chancellor J'mpok traveled to Gornar and together with Slathis made a public announcement of the severity of Species 8472's infiltration of the Hegemony, then proceeded to execute the infiltrators. Despite demands by hardliners on the Klingon High Council, J'mpok chose not to execute the Gorn royal family, instead offering them self-rule as a client state of the Empire. Slathis accepted and was given a non-voting seat on the Council. (ST website: The Path to 2409)
In their capacity as a Klingon client state, Gorn naval forces attacked Sherman's Planet on Stardate 82626.64 in 2405, at the start of the Third Federation-Klingon War. Starfleet repelled the attack. The same year, King Slathis negotiated a nonaggression pact between the Klingons and the Nausicaans he had formerly employed.