- "The grubs hit Jilane hard. The garrison was overrun and the C.O ordered his men to abandon the evac op. It was a hard call... and according to doctrine, the correct call. But it wasn't the right one."
- —Marcus Fenix, reading the report on Jilane
The city of Jilane was a COG controlled city. It hosted major breeding Farms. It was overrun by Locust forces some time after the Lightmass Offensive. Delta-One and Sigma-One, with the help of the "scout" Alex, were sent to take on the Locust Horde.
The city of Jilane was the birthplace of Alex Brand, who, like many young girls, were drafted into Chairman Richard Prescott's re-population plan. The city was the center of the "Farms", where young women would be artificially inseminated. If that did not work, the "Old Fashion" way was used. The best of the Gears were recruited to impregnate the young girls. When a girl failed to be impregnated, they where deemed "Barren" and sent into the army; which protected the city with a small garrison of Gears. Around 14 A.E., the city was attacked by an overwhelming Locust army which led to COG abandonment, leaving the children and women in the farms to fend for themselves; which incurred the Jilane Massacre. Four months after the massacre, the COG sent Delta-One, with elements of Foxtrot and Sigma-One, to investigate a beacon.