The First Cabal was one of the Council's first projects, composed of the best and brightest of each Tradition and lead by Teomim of the Solificati. The First Cabal's purpose was to go forth in the world as ambassadors from the Traditions to mages and Sleepers alike: they would fight the Council's enemies and bear its message of hope to its friends. It was also meant to encourage the formation of other inter-Tradition cabals, to strengthen and unify the Council.
The March of the Nine met mixed success. The First Cabal was riven by interpersonal conflicts, most of which were the perhaps inevitable result of nine strong-willed people from very different cultures trying to work together. They also committed missteps, such as the burning of Garouche and the failure to stop Tezghul the Insane (though they did destroy his stronghold, Kupala Alka). Teomim's intense personal charisma was enough to hold the cabal together at first, but over time he himself began to doubt its purpose. His colleagues, and the Traditions they represented, were unable to unite behind a common cause, and it seemed inevitable to him that the smaller but more cohesive Order of Reason would eventually prevail.
Akrites Salonikas, the Cult of Ecstasy's representative in the cabal, foresaw that Teomim would eventually betray them. However, he had also experienced a vision of a dark future in which Teomim ruled the world as a tyrant. He conferred with other members of the Cult, and they agreed that, if Teomim betrayed the First Cabal, the Council would almost certainly execute him, thus preventing the dark future. Salonikas thus told no one of either vision.
In early 1470, the First Cabal were camped in Narbonne when Teomim abandoned them. The remaining members argued about what to do next for nearly two weeks. Walking Hawk had a vision of falling stars that seemed to clearly presage the end of the cabal, and shared this vision with the others.
The following morning, Heylel returned with troops from the Cabal of Pure Thought in tow, including the Legion du Triumph and the Iron Hounds, intending to capture his former companions. Salonikas fled to alert the Council; three of the remaining cabal members were killed resisting capture, and the rest imprisoned in Brienne Tower and tortured. Salonikas lead the rescue mission, but by then only Walking Hawk, Eloine and Bernadette survived. The infant children of Teomim and Eloine, taken into custody along with her, were never found.
Shortly after this, Heylel either was captured or surrendered himself to the Council. During his trial, he denied the rumors that he had turned Nephandus or engaged in Infernalism, but admitted to his betrayal and insisted he had the greater good of the Traditions at heart. He dressed all in white, as a symbol of his good intentions, something his supporters imitated. In November 1470, Teomim was executed by Gilgul, destroying his avatars permanently. From then on, the title Thoabath ("Abomination") was appended to his name in all Council records.
The Traditions were badly shaken by the Great Betrayal. The Solificati collapsed into infighting, and their primus, Luis de Estes, was assassinated. Their self-destruction would leave the Seat of Matter vacant for over four hundred years. Rumors flew alleging that Salonikas was in league with Teomim. The city of Concordia in Horizon was separated into Tradition-specific wards, and the Council nearly fragmented.
Salonikas, Bernadette, Eloine and Walking Hawk went their separate ways after Teomim's trial, and lived the rest of their lives in relative isolation. Their own accounts of the Great Betrayal, as well as Teomim's testimony in his own defense, were eventually complied into an edited volume called The Fragile Path by Porthos Fitz-Empress.