http://memory-beta.wikia.com/wiki/Regulus wrote:
<<Early in the 23rd century, one of the worlds of Regulus was governed by Romulans, as an outpost of the Romulan Star Empire. A population of Regulan humanoids lived under Romulan rule, including the unlucky J'Onn, who was exiled to Nimbus III with his wife after being convicted of embezzlement. (TOS novelization: The Final Frontier)
By the 2280s, Regulus was the location of a Starfleet Intelligence base. part of the Starfleet Intelligence sector 3 command based at nearby Starbase 15. (ST roleplay module: Star Fleet Intelligence Manual)
Regulus III was home to a humanoid civilization who had established relations with the United Federation of Planets. These Human-descended inhabitants had developed a different naming system for the astronomical bodies in the system, naming their home star as Ra and their homeworld as Khepri. The other planets in the system were also given the names of various Egyptian deities. (TOS - Star Trek II Short Stories short story: "The Blaze of Glory")
In the 2260s, Regulus was the site of a battle between the USS Intrepid and the Klingon flagship, IKS Hakask. Suvuk, the captain of Intrepid, scored a decisive victory after offering himself as a hostage, when he escaped from his Klingon captors and stole the entire library computer database from Hakask, shortly before the Organians intervened and disabled weapons on both sides. Suvuk won the Pentares Peace Commendation and a promotion to admiral for his action at Regulus. (TOS novel: My Enemy, My Ally)
During the invasion of the Borg Collective in 2381, Starfleet established its last line of defenses at Regulus. There was no core planet evacuation plan developed by Starfleet should the Borg break through the Regulus defenses. (ST - Destiny novel: Gods of Night)
The Regulus system has been listed as a home to the Caitians, although their home system has been identified as 15 Lyncis in other sources.
System
* Regulus I (Horus)
* Regulus II (Arodi/Osiris)
* Regulus III (Khepri)
* Regulus IV (Khonsu)
* Regulus V (Ptah)
* Regulus VI (Rhamses)
* Regulus VII (Nefertari)
* Regulus VIII (M-113, fourth planet from UFC-113)
* Regulus IX
* Regulus X
* Regulus XI
* Regulus XII
* Regulus XIII