Taris was a Romulan sub-commander and the commanding officer of the Romulan warbird IRW Haakona in the 2360s. In 2365, her ship discovered the USS Enterprise-D in the Neutral Zone when it was searching for the USS Yamato, which had violated the Neutral Zone in search of Iconia and later suffered catastrophic systems failures after encountering an Iconian probe, leading to its destruction.
Taris ordered the Enterprise-D to leave the Neutral Zone and later, gave the order to fire on the Enterprise-D when she detected an away team transporting to the planet's surface. However, Taris' ship also became infected by the Iconian probe and its weapons disarmed at the last possible moment under its influence.
Captain Jean-Luc Picard led an away mission to the surface of the Iconian homeworld in order to destroy the Iconian gateway so that it would not fall into Romulan hands. He stepped through the gateway before its destruction and ended up on Taris' bridge. Taris believed that the Enterprise-D was responsible for the malfunctions it was suffering, and informed Picard that a self-destruct sequence had begun which she was unable to stop. She stated that at least Picard would also die with her. However, by this time the Enterprise-D systems have been restored and Picard was beamed to safety. Geordi La Forge instructed her how she could protect her ship from the probe's effects. (TNG: "Contagion")
In the backstory of Star Trek Online, Taris rose to the rank of admiral and was among those responsible for the Hobus supernova (β) in 2387, which resulted in the destruction of Romulus and Remus. In the aftermath, she becomes praetor, but is ousted by Sela. 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.