|A Coridanite ambassador in 2155|
|The chancellor of Coridan in 2151|
The Coridans traded with the Orions for centuries prior to 2155. By 2151, the planet Coridan had a population of three billion with most of the population being concentrated in several cities in the equatorial region. The capital city was surrounded by a shantytown, and there were almost as many bio-signs outside the city as there were within it. As of 2151, the Coridans also had the largest starship construction yards in the sector. However, the planet was also embroiled in a conflict between rebel forces supported by the Andorians, and the government under Chancellor Kalev backed by the Vulcans. The Vulcan agenda was to keep the planet's chancellorship stable, which in turn assured its dilithium exports to Vulcan. (ENT: "Shadows of P'Jem", "Demons")
In 2152, Coridans were represented at the Interspecies Medical Exchange conference on Dekendi III. At one point, the "Coridan Genome Conference" was rescheduled to 1400 hours and changed to auditorium six. This was announced on a speaker system inside the conference building. (ENT: "Stigma")
The Babel Conference in 2268 was to consider their admission into the United Federation of Planets. The planet was considered underpopulated at that time, making it susceptible to illegal mining operations. Federation membership would provide the planet with protection under interstellar law. (TOS: "Journey to Babel"; TAS: "The Pirates of Orion")
Mining operations were maintained there by the Orions and Tellarites, among others, a concern that led some to think they should be denied Federation membership. Ambassador Sarek of Vulcan spoke in favor of admittance, and was given credit for passage of the measure. Coridan joined the Federation that same year. (TNG: "Sarek")
- See Coridanites
The appearance of the Coridans/Coridanites drastically changed from "Shadows of P'Jem" to "Demons," the species' only two appearances. In "Journey to Babel," Sarek spoke of the "Coridan planets" in the plural suggesting the possibility of two species. Also the ambassador in "Demons" only mentioned Coridan in passing and never identified himself as Coridan. In fact, he bears some resemblance to a Zaranite.
The reference book The Worlds of the Federation displays a profile of the Coridan system, showing Coridan III as the homeworld of the species, and four more planets as colonies, spreading the population thin over the entire system. Coridans were a frequently targeted for raids by other species and the asteroid belt and ninth planet of the system were illegally mined by the Orions and the Tellarites. A profile picture of a Coridan male shows them to be human-like in appearance.
In the Star Trek: Enterprise "relaunch" novel The Good That Men Do, Coridan (referred to as Coridan Prime) is at the center of a major plot point in the story. The novel also reveals details hereto unresolved by canon productions.
The physiological differences between the Coridanites depicted in "Shadows of P'Jem" and those seen in "Demons" is attributed to a special diplomatic headdress worn by those seen in the latter episode. The novel describes the headdress as "a metallic material shaped into the stark features of a humanoid skull" with "overlapping bands of chitinous, lobster-colored fabric" that wraps around the cranium. The overall appearance is said to give the Coridan a vaguely crustacean appearance.
Taking steps to explain Coridan's 23rd century population issues, the novel depicts 22nd century Coridan as a world rich in resources, on the verge of achieving warp 7, and soon to be allied with the Coalition of Planets. To prevent such advances from spreading to other Coalition of Planets member worlds, the Romulans launch a vicious attack on Coridan, flying a vessel into the planet at maximum warp. Anti-matter from the suicide attackers' ship mixes with Coridan's abundance of dilithium, causing a fireball that spreads across the planet, killing billions. The planet's population is said to be further depleted by civil wars that continue after the Romulan attack.
In the ICON Star Trek: The Original Series RPG corebook, Coridan is described as a cold dry class M world with a chronically corrupt government in the 2260s.