- You may also be looking for Iconian (Guardians).
The Iconians were an ancient and highly advanced civilization that was thought destroyed approximately 200,000 years ago by orbital bombardment of their homeworld, Iconia. (Star Trek: The Next Generation)
All over the galaxy, remnants of the Iconians remain, in temples, murals, and the gateways. Ancient texts called the Iconians "Demons of Air and Darkness", who were said to have the ability to appear at will on far-flung planets without the use of starships. In the 24th century, it was discovered that the Iconians used a network of gateways that made this instantaneous transport possible. Through the gateways, Iconian influence spread at least as far as the Gamma Quadrant, and probably further. (TNG: "Contagion", DS9: "To the Death")
In the early 25th century, the Iconians were discovered to be behind several plots against races in the Alpha Quadrant, including being the causes of the destruction of Romulus and driving the Undine and Tholians against the Klingon Empire and the Federation. In the Delta Quadrant, the Iconians were hinted at being behind the Blugill infection of the Vaadwaur leadership in an effort to define them as a feared power. (Star Trek Online)
- See: Iconian (Guardians)
The Iconians were also known as Guardians, Time Lords, Ancients and Oq'rat"jahm, in their native language. They were an incredibly advanced society of beings made up of several humanoid and non-humanoid races who eventually became so attuned to temporal mechanics that they evolved into a higher plane of existence, actually becoming part of the fabric of time and space. Before fighting in the Time War and mutating through biological weapons into corrupt and unstable warriors, they were the dominant part of a vast, peaceful extra-galactic alliance also involving the Preserver race. Those Guardians that remained in corporeal form were the mysterious ancient progenitors that seeded the Milky Way Galaxy with humanoid life.
When the USS Helen became trapped in the Triangulum Galaxy, they made contact with a species called the Pasori, who worshipped a sect of Iconians that had come to the Gamma Quadrant of the Triangulum Galaxy prior to the bombardment of Iconia. According to the local mythology, these Iconians had come bringing knowledge and technology to the inhabitants of the Triangulum Galaxy, and established themselves as peacekeepers among the factions of the Galaxy.
Following the bombardment of Iconia, the surviving Iconians arrived in Triangulum. There was a period of war between the two groups of Iconians, that pushed the more peacefull faction almost completely out of that area of space, forcing them to settle on Tomek Dai, a Rogue Planet that served as their stronghold world. At an unknown point in the last 200,000 years, the Iconians left the Triangulum Galaxy to parts unknown.
One faction of Iconians were a ruthless race that conquered planets and species during their reign over this area of the galaxy up until the bombardment of their homeworld. Rumors started circulating in 2409 that they where starting to return to the Alpha Quadrant, and were involved with the destruction of Romulus and Remus.