Prophet of Solemnity

This unidentified Hierarch was one of the High Prophets of the Covenant during or after 2142 but before the Human-Covenant War.

History
This Hierarch called an audience with then-current Arbiter Fal 'Chavamee, who believed that the Sangheili had forsaken their honor during their service to the Covenant; more pointedly, 'Chavamee had refused to acknowledge the Covenant religion. The Hierarch urged 'Chavamee to recant his views, but the Arbiter defiantly claimed the Great Journey, the cornerstone of Covenant faith, to be a lie. After the audience had ended, the Hierarch declared 'Chavamee a heretic and recruited the Arbiter's clansman Haka to kill his clan leader.

Haka dispatched a team of assassins to kill the Arbiter, though 'Chavamee expected this turn of events and killed them. Haka then coerced Roh, one of Fal's close friends, into killing Fal's wife, Han. After discovering Haka's treachery, Fal defeated a large Covenant military detachment that had been sent to kill him, then dueled Haka atop a Forerunner structure; both duelists were killed. After 'Chavamee's death, the Hierarch declared that the title of Arbiter, previously a badge of honor, would thenceforth be a mark of shame.

Conjecture
This Hierarch bore a very remarkable resemblance to the Prophet of Truth in both appearance and personality. He is even credited as such in the Japanese language version of the episode. This may suggest that he was the namesake of the latter Prophet, as the Hierarchs choose their regnal names from those of one of their predecessors. However, as he is simply credited as "the Prophet" in the English dub of the episode, this theory is of dubious canonicity.