"Born" at the UNSC's Sydney Synthetic Intellect Institute in 2551, Tinuviel is a prototype eighth-generation "dumb" artificial intelligence. Throughout her life, she has served mostly in combat roles - initially as a ship combat AI aboard the UNSC Aeneas, then attached to the Spartan-II Indigo Team after its destruction. Although initially confined to the SSII to study anomalies in her programming, she eventually arranged for her return to a combat role aboard the UNSC Ajax, the second Herald-class ship she was to serve aboard. Although she only saw three battles of the Human-Covenant War - Minorca, Earth, and Ares IV - she played a much larger part in the subsequent War of Vengeance beginning in 2555.