Prophet of Truth

The Prophet of Truth is the leader of three Hierachs that lead the Covenant High Council. He is the most enigmatic of the three.

Biography
Truth is much younger than the High Prophet of Mercy, but only slightly older than the High Prophet of Regret.

Justification of the belief that he is the most powerful of the three high prophets comes from scenes such as the opening cinematic sequences in 'Heretic', and scenes during the opening of 'The Arbiter'. His authority is also clearly exhibited in other ways, for example, it is he who airs the transmisson informing the Covenant that the Great Journey is about to begin (before being interrupted by Master Chief at the start of 'Gravemind').

Truth was the first Prophet ever mentioned by name, at the end of Halo: First Strike. He waited in High Charity on the Step of Silence for Tartarus to come and report on the status of the teams searching for the Forerunner Crystal. He then ordered the teams that searched for them executed.

Truth did not think highly of the Prophet of Regret's inexperience. It is not clear just how much younger Regret is than Truth, but neither of them were born when the Prophet of Mercy was elected to the council. He wrote letters to Mercy complaining of Regret's rashness, one of which appeared in Conversations from the Universe.

Truth was first seen in Halo 2, during the trial of the Supreme Commander of the Fleet of Particular Justice. With a nod, he ignored the requests of Regret and the council to execute the Commander, and instead chose to make him an Arbiter. He then sent his new Arbiter against the Heretic rebellion forming on the nearby Gas Mine.

While on Installation 05, Regret transmitted an apology to Truth, apologizing for his reckless attack on Earth. Truth responded angrily, saying that it was only Mercy who had stopped Truth from publicly condeming Regret. Nevertheless, High Charity and its fleet rushed to Installation 05 and released a fleet of Phantom dropships full of forces to save Regret from the humans who had overwhelmed Regret's own army. His sermons were interrupted when the Chief burst in, and managed to attack and kill him. The rescue Phantoms were called back by Truth, and instead a Covenant cruiser quickly destroyed the temple with an energy beam.

After Regret was killed by the Master Chief, Truth began replacing the Elites with the Brutes as the Prophets' protectors. This ultimately led to a civil war throughout the Covenant. Shortly thereafter, while Truth was addressing the Covenant about the Flood, The Index, and The Great Journey, the Chief, who was teleported to High Charity by Gravemind, attempted to assassinate him and the High Prophet of Mercy, but their Brute bodyguards covered their escape.

He, Mercy, Tartarus, and the captured Commander Miranda Keyes and Sergeant Johnson were about to take Phantom dropships to the surface of Installation 05 when they were attaked by Flood infection forms. Truth allowed Mercy to die when he was infected, and instead, as it looked as though High Charity would fall to the Flood, he fled in the Forerunner Ship. When the Chief questioned dying Mercy, he said that Truth was going to Earth "to finish what we started".

As of Halo 2, Truth is the only High Prophet (and possibly only Prophet) alive.

Motives
The motives for Truth's actions have been called into question as one of the biggest mysteries of the Halo universe. His choices in allowing both Mercy and Regret die seem to suggest that he wants supreme power over the entire Covenant, yet he demonstrates throughout the storyline that he already has supreme power, even over the other High Prophets.

Another action of his that is a mystery is the replacing of the Elites with the Brutes in Covenant society. Truth's only reason for why Brutes replaced Elites was that Elites "could no longer guarantee the safety" of the Prophets due to the death of Regret, but it is already clear that Regret's death was a combination of his own recklessness and Truth's recall of the dropships that were inbound to save him.

Truth's belief in the Covenant religion is also in question. He appears to have had ample time to scrutenize 343 Guilty Spark after it was captured from the Gas Mine, and it is likely that Spark "edified" Truth in the same way as Sesa 'Refumee, who led a rebellion against the religion. If this is the case, it is also unclear then exactly why Truth wishes to activate the Halos and kill all life, including his own empire, if he knows there is no Great Journey.

Quotes

 * "The Council decreed that you be hung by your entrails, and have your corpse paraded through the city. But ultimately...the terms of your execution are up to me." -To the future Arbiter
 * "Ah, politics. How tiresome."
 * "The Great Journey waits for no-one, brother. Not even you."  -To the Prophet of Mercy, as the latter dies
 * "There are those who said this day [the rise of the Brutes] would never come. What have they to say now?" -Addressing the Covenant