Lepidus was a Brute Shipmaster of the CCS-class Battlecruiser Triumphant Declaration in the Fleet of Furious Redemption.
Lepidus was the first Covenant member to hear of the Key of Osanalan. He then informed the Prophet of Truth of the Key, which sparked the Battle of Cleveland. He appeared to be reporting to Truth aboard the Forerunner Dreadnought, where Master Chief Petty Officer John 117 attempted to assassinate Truth.
Truth escaped, so did Shipmaster Lepidus, but every Covenant unit who stayed in the room were massacred by John 117. Lepidus was later seen aboard the Triumphant Declaration in the orbit of Mars, furious at Colonel James Ackerson for tricking the Covenant into believing in the Key of Osanalan and killed the Colonel with his Brute Combat Knife.