There are some things even the Hierarchs do not understand.
~ Thel 'Vadam to Tartarus.

The Prophet Hierarchs are leaders of the Covenant High Council and rulers of the entire Covenant Empire. They are elected by Councilors each age. Hierarchs can always be seen being protected by Honor Guards or Brute Bodyguards.

Known Hierarchs

Prophet of Truth

Main Article: Prophet of Truth

Originally holding the position as Minister of Fortitude, Truth appeared as the leader of the last set of Hierarchs as well as ruler of the entire Covenant Empire. Truth ultimately betrayed the Elites, replacing them with the Brutes who became the Prophets new protectors as well as the Covenant's new military leaders. Truth led a Covenant fleet on Earth aboard his Forerunner Dreadnaught, although he went to the Ark at Installation 00 where he planned to activate the Halo Array and fulfill the Covenant's religion. He held Sergeant Johnson captive and planned to use him to activate the rings, and had Brute Bodyguards to protect them as well as a Chieftain who was killed by the Arbiter and Chief. The Arbiter personally confronted Truth while John 117 deactivated the Halo Array which angered the Prophet, Arbiter then killed Truth by impaling him with his Energy Sword as revenge for betraying the Elites.

Prophet of Mercy

Main Article: Prophet of Mercy

Mercy was originally a Philologist, and soon became a Hierarch alongside Truth and Regret as the eldest of the three. He followed Truth around and agreed with what he said, but he was soon betrayed by Truth himself and was attacked by the Flood, before being left to die on High Charity.

Prophet of Regret

Main Article: Prophet of Regret

Prophet of Regret Villain

Prophet of Regret as seen in Halo Wars.

Regret was originally the Vice Minister of Tranquility before blackmailing one of the Hierarchs to being promoted to a Hierarch himself. He intended on reviving a Forerunner fleet on Harvest with the help of an Arbiter: Ripa 'Moramee. He later went to lead a Covenant fleet on Earth and soon left to go to Installation 05, where he planned to activate Halo but failed his mission and was assassinated by John 117.

           Halo Villains

The Flood | Huragok | Mgalekgolo | Jiralhanae | Kig-Yar | Sangheili | San Shyuum |

Covenant Empire
Covenant High Council: Prophet of Truth | Prophet of Mercy | Prophet of Regret

Covenant Sangheili: Ardo 'Moretumee | Bako 'Ikaporamee | Field Marshal | Harka | Lat 'Ravamee | Luro 'Taralumee | Merg Vol | Ontomee | Re'gish Wamik | Rho 'Barutamee | Ripa 'Moramee | Rtas Vadum | Thel 'Vadam

Covenant Jiralhanae: Lepidus | Parabum | Tartarus

Storm Covenant
The Didact | Jul Mdama | Gek 'Lhar | Parg Vol | Kitun 'Arach

Cortana | Warden Eternal | Guardians | Prometheans

The Banished
Atriox | Decimus | Let 'Volir

Office of Naval Intelligence
Jameson Locke | James Ackerson

Jerald Mulkey Ander | Robert Watts

343 Guilty Spark | Commissioner Kinsler | Gravemind | Heretics (Sesa Refumee) |