The First Mistridge Tribunal was not so grand as the name implies. Hermetic Master Baldric LaSalle, Master Valoran of the Celestial Chorus, Lady Nightshade of Verbena and Sh'zar the Seer met in the ruins of the Mistridge Covenant on December 31, 1439. Overnight, they discussed the looming threat of the Order of Reason, and the need for unity among the various factions of mysically-minded mages. The three Europeans agreed to a truce among their orders, and then left Mistridge to seek out other mages who might also join an alliance.
The Second Mistridge Tribunal in 1449 was a larger affair, and included future leaders of the Council such as Star-of-Eagles, Ali-beh-shaar, Naioba, Chalech, Diplomate Luis and Wu Jin. This was where the Dreamspeakers Tradition technically formed, as Star-of-Eagles and Naioba recognized their common orientation towards the magic of the spirits (and the profound lack of understanding the other mages had for both their magic and their cultures). This tribunal was brought to a premature end when the Craftmasons attacked the site; while the attack was rebuffed, it became clear that any future meetings needed to take place in a more secure location, and the group set out to build the realm of Horizon in order to host the Grand Convocation.