2509

2509 was a year in the 2500s in the 26th century.

Unknown

 * By this year, many rebel cells had combined under the leadership of Robert Watts, proudly referring to themselves at the United Rebel Front.
 * The M850 Grizzly enters service with the UNSC.

Circa 2509
Two years after Catherine Halsey met Elias Carver
 * Dr. Elias Carver commits suicide.