She was the commanding officer of the Romulan warbird Haakona in the 2360s. In 2365, her ship discovered the Federation ship USS Yamato inside the Neutral Zone when it was trying to identify the planet Iconia. She eventually found it when it made a rendezvous with the USS Enterprise-D and watched it explode after downloading some of the contents of its computer while cloaked. Unfortunately, the computer contents contained an Iconian program that re-writes alien programming, affecting the Haakona the same way as the Yamato.
Despite this, Taris ordered the Enterprise-D to leave the Neutral Zone and attempted to claim the planet. However, the Haakona was as unresponsive as the Enterprise was, in fact, the self-destruct procedure had been activated. Captain Jean-Luc Picard, on the planet, discovered an Iconian gateway and destroyed it so that it would not fall into Romulan hands. He stepped through the gateway which was pointed at the Haakona's bridge. However, by this time the Enterprise-D systems had been restored and Picard was beamed back. Geordi La Forge instructed her crew how to remove the probe's effects. (TNG: "Contagion")
This was the first of several Star Trek roles for actress Carolyn Seymour, who later played another Romulan named Toreth in the episode "Face of the Enemy", with the production staff creating a new character in the belief that Taris had been killed. (Star Trek: The Next Generation Companion (1st ed., p. 234))
In the backstory of Star Trek Online, Taris rose to the rank of admiral and was among those responsible for the Supernova of 2387, which resulted in the destruction of Romulus and Remus. In the aftermath, she became praetor following victories against the Klingons, but was eventually ousted in favor of Sela by a military coup led by General Velal. It is revealed that both Taris and her science officer, Hakeev, became willing servants of the Iconians as a result of their mission to Iconia, and seek to bring about their return. Taris is first confronted in 2409 by Romulan Republic players at a secret base in the remnants of the Hobus system, which she escapes via a gateway leading to Iconia, where she is captured by Starfleet. Sent to a secret prison facility, Taris is taken from her cell during an uprising, with only an Iconian energy signature as a clue to her fate. The next year, she is found in an Iconian-built Dyson sphere in the Andromeda Galaxy, where she is kicked off an observation platform by Sela, presumably falling to her death.