Sanctum of the Hierarchs

The Sanctum of the Hierarchs is the name given to the private quarters of the High Prophets on High Charity. They were restricted to virtually all other creatures, except the Honor Guard, San 'Shyuum and Sangheili Councilors and high-ranking Covenant officers, such as Special Operations Commanders and Arbiters.

Description
The Sanctum consisted of many rooms, the most important being the inner chamber. The Sanctum featured unique architecture, highly ornamented doors and various other luxuries. The inner chamber of the Sanctum had several entrances; one was via a lift in the High Council Chamber, and another was a large hallway where dozens of Honor Guards used to stand watch. The higher levels of the Sanctum, or the Far Tower, also included three tenders for Phantom dropships. The center of the inner room also featured a holotank which also had another mechanisms, such as serving as a stasis field emitter.

One of the rooms in the sanctum was a massive chamber with its walls, floor, and ceiling ornamented with smooth glass from all the worlds conquered by the Covenant. This chamber was a large, round room with an illuminated pedestal in the center. On the perimeter of the room, there was space for three hundred Honor Guard Sangheili, should a Prophet be present.

History
After Operation: FIRST STRIKE, the High Prophet of Truth and Tartarus, Chieftain of the Jiralhanae discussed the events that took place on Installation 04, as well as the fate of the future Arbiter, the destruction of the Unyielding Hierophant and the Covenant personnel who survived it, in the Sanctum.

Many events took place here, including the Changing of the Guard when the Jiralhanae supplanted the Sangheili as the Honor Guards and minders of the Prophets, after the assassination of the Prophet of Regret. It was here that the Prophet of Truth and the Prophet of Mercy explained to the Arbiter his task of landing on the surface of Installation 05 and retrieving the Index from the Flood infested Library, which took place in two levels through the Sentinel Wall and the Quarantine Zone.

In the end, the Flood used Pelican dropships to land in the Sanctum. It was one of the first areas to be infested; it was filled with Flood spores and biomass when the Master Chief traversed the area in search of the High Prophet of Truth.

When John-117 returned to High Charity in order to rescue Cortana, she was being held inside a stasis field in the holotank in the center of the Sanctum. The room had been dramatically altered by the Flood infestation: there were widespread structural failures that occurred as a result of the Flood infestation as well as High Charity colliding with the surface of Installation 00.

Trivia

 * In Halo 2 when you enter the room, you can see a dead Elite Minor with an Energy Sword on the nearby obelisk and another on a pronged pedestal.
 * During the Sacred Icon cutscene, 343 Guilty Spark can be seen floating in the holotank. Whether he is floating on his own or a stasis field is holding him is unknown.
 * In the Halo 3 campaign level Cortana, John 117 passes through one of High Charity's reactor rooms to get to the sanctum in order to save Cortana, which suggests that the two rooms are located quite closely to each other.

List of appearances

 * Halo: First Strike
 * Halo 2
 * Halo 3