The Second Illumination was a time period during the Covenant's history. Little is known about the events of this era, other than the Commando Harness being modeled after a group of Covenant heroes from this period. It is likely that this was a time of war when the Covenant were fighting another species rather than the humans. It is also possible that it may have been a time when the Covenant was formed, which would make the First Illumination the time when the Elites first found and began worshipping Forerunner artifacts.