The Arretians (also called Sargonians) were an ancient humanoid progenitor species from the planet Arret with characteristics that would come to be known as Vulcanoid in the modern age. Around 600,000 years ago they colonized much of the known galaxy, especially in the Alpha and Beta Quadrants and formed the Arretian Empire.
Their empire, and ultimately their species, was destroyed in a cataclysmic war that drove the survivors to implanet their consciousness in special receptacles. Only three of these, Sargon, Thalassa and Henoch, survived into the 23rd century, when they were discovered by the USS Enterprise. (TOS: "Return to Tomorrow"; Last Unicorn Games RPG: All Our Yesterdays: The Time Travel Sourcebook, Star Trek: Department of Temporal Investigations novel: Watching the Clock)
Among the worlds the Arretian Empire either colonized or seeded with life were Vulcan and Mintaka IV. Other worlds showing possible Sargonian influence include Rigel V.and Halana. The Sargonians may in fact be the origins of the Vhorani myths of the Romulan and proto-Vulcan peoples, as well as the Overseers worshipped by the Mintakans.
In the late 24th century, Timothy Sinclair studied many Vulcanoid cultures, including the Arretians, and wrote a research paper called From Arret to Mintaka: In the Path of the Vhorani. (Star Trek: Pendragon: "Starkindler")