Prophetess Supreme was a Centauri title bestowed by the Emperor himself to a chosen Prophetess who traditionally resides in Tuwain. The title is a great honor and entitles the Prophetess to a great deal of money, privilege and influence until the day she dies. With the passing of each prophetess, another comes to Tuwain to take her place and on that day, the emperor of the day would personally oversee her enshrinement as prophetess supreme, travelling by the very same carriage and along the same road taken by Morell to Tuwain.
The tradition dates back to around the 11th Century and the Emperor Morell who's life was saved by a Prophetess of Tuwain named Malia. Morell encountered the prophetess in the third year of his reign while passing through Tuwain with his soldiers. They were on their way back to the palace after putting down an attempted uprising on the Scoria Plains and stopped by the river Tuwain to water their dromes and rest after the long march from the sea. Malia approached the Emperor and warned Morell that a dagger would strike "to his heart from near his heart" and that "only the crescent moon hidden in darkness" would save him.
After returning to the Royal Palace Morell hosted a great dinner, during which Morell's nephew Elfeni stood to offer a toast. As he did so Morell noticed his nephew was wearing a broached shaped like a crescent moon and that the broach was hidden by the shadow of Elfeni's arm. Morell called for the Palace Guard who apprehended Elfeni just as he drew a blade to assassinate his uncle. Elfeni later confessed to be party to a secret alliance with others who had attempted to bring about a civil war which would end with Elfeni replacing Morell as Emperor.
Morell later returned to Tuwain and gave the prophetess Malia a tenth share of his fortune and pledged that for as long as there was an Emperor of the Centauri Republic, there would always be a prophetess of Tuwain held in royal favour, revered and honored as the Prophetess Supreme and it was so.
In 2262, the Prophetess Supreme was killed during the bombardment of Centauri Prime. Six days later the newly coronated Emperor Mollari II presided over the enshrinement ceremony of Lady Delasi Miro as the new Prophetess Supreme at Tuwain. In truth, Delasi was not an actual Prophetess, though she was however the guardian of the young Prophetess Shiri Dei. Mollari publicly discredited Shiri and proclaimed the ambitious manipulator Delasi to be the "true" Prophetess in order to free Shiri from Delasi and allow the young woman to marry the man she loved and with the Emperor's quiet assistance, restore House Dei.