From Halopedia, the Halo wiki
Conflict:
Human-Covenant War
Date:
Unknown (sometime from 2544 to 2552)
Location:
Imber
United Nations Space Command
Covenant
at least one SPARTAN, Kelly-087
Unknown
Operation: DEVIL FREEDOM was a UNSC operation carried out on the human colony of Imber when it came under attack by the Covenant sometime near the end of the Human-Covenant War. Objectives included the evacuation of civilians and the targeting of Covenant landing craft for orbital bombardment.[1]