Built in a Duwani Mechanical Products factory 4000 years ago, T3-R9 began his existence as a simple utility droid. Designed for repair and general maintenance duties, the T3-series worked at their best aboard starships. Such was not the to be for R9 who was assigned to the Jedi Temple on Coruscant, specifically to one of the Jedi, a young man by the name of Vandara. It swiftly proved to be a less than pleasant partnership, as Vandara did not speak or understand binary, and expressed distaste for the droid at worst, complete dismissal at best.
Nonetheless, the little droid worked alongside a rather ragtag bunch of Republic soldiers, mercenaries, Jedi, and even a senator (briefly) on a mission to investigate and discover Jedi imprisoned during the war with the Sith Triumvirate. It was during this time that he began to develop a personality of his own, possessing a fascination and talent for gambling. It often proved to be a boon to his companions when they were low on credits. Of course, this didn't stop them from considering selling the droid.
Despite his programming, he steadily developed a disdain for organics who treated him as little more than a talking appliance, and R9 often entertained the idea of blowing his 'friends' out of the ship's airlocks. Of course, he never did so, having formed a camaraderie with them despite the many difficulties they all faced in working with one another. His personality continued to emerge, thanks in large part to a technician by the name of Bidon Vask who worked in the Jedi Temple. Vask and R9 had developed a relationship during the droid's tenure at the Temple, and in exchange for being able to witness the team's holo-recorded adventures, he forewent R9's scheduled mind wipes.
The little droid has led an interesting life, involved in a number of adventures and vital missions to the republic during his many years of service. He fought against a Sith Lord, defeated a sentient spaceship, and helped to run a fight club within Coruscant's lower levels. Not all of his accomplishments have been.. praise-worthy, obviously. In fact, T3-R9 remains noted in the Senate Archives as one of the few droids to publicly insult and berate a senator and avoid being dismantled as a result:
Of course, records of any Republic soldier's activities, especially those of a droid, are difficult to keep track of. At some point during a crisis in the Enorath Sector, information on R9 and his fellow members of Republic Intelligence become increasingly difficult to find. Of course, this is not entirely unexpected of documentation several thousand years old. Many such droids from those days long past are no longer functional, serving as pieces of prized collections rather than continuing the functions that they were built for.
It is entirely possible that such was the fate of this particular T3 unit...