Operation: TRIUMVIRATE

Operation: TRIUMVIRATE was an anti-Insurrectionist operation that took place on Taradia in the early years of the Insurrection. It was the first official operation involving the ORION program's experimental SPARTAN-I operatives.
Lieutenant Hector Thornhill was the only SPARTAN-I deployed during the operation; ORION's existence was at the time undisclosed to the UNSC.
TRIUMVIRATE was initially intended as a covert operation that would allow UNSC forces to capture the rebel information dealer, David Kahn. About 400 soldiers were deployed into the city of Three Gates to trap him. However, Kahn unleashed a network of artillery that devastated the city and forced the UNSC into open engagement, resulting in high collateral damage and civilian casualties.
The following battles took place mainly in Three Gates. On May 10, 2491, all civilians were evacuated, turning the city into an all-out war zone. On May 12, a team led by Thornhill located Kahn, and after a short fight, Kahn escaped on board a Pelican with Thornhill captive.
Kahn hid in New Celje until the UNSC tracked him down on June 25. However, Thornhill managed to escape and kill him. The battle ended three days later with most of the rebel soldiers killed and the rest forced into submission.