Antonius the Gaul, originally known as Antiorix before he latinized his name, was a powerful Ventrue methuselah. Around 312 he joined with Michael and Dracon to become a vampiric Triumvirate that ruled over Constantinople until being betrayed and destroyed in 796.
During his early times, in Gaul, Antiorix ruled along his broodmate Erik Eigermann over the locals before the Romans invaded their lands. Recognizing the ideals of his clan among the Romans (as well as intrigued by the powerful Toreador Beshter), he left Gaul to join the Eternal Senate, dooming his people to be subjugated. When Beshter became fascinated by the new faith of Christianity, it was Antonius who provided the advice and support that made envisioning the Dream possible.
As Beshter, now calling himself Michael, become lost in wonder, Antonius proposed the specifics of building a new and strong empire. Their relationship was not without its pitfalls, though. The most severe was the arrival of the strange Tzimisce known as the Dracon. This mutable creature of passion and vision was almost the complete opposite to the pragmatic and solid Antonius, and was equally irresistible to Michael. Michael soon became "the Wanderer" once again, travelling between the Roman palace of Antonius and the Cypriot haven of the Dracon.
Antonius busied himself with the task of forging a new empire, all the while trying to regain Michael's undivided attention. Antonius was the first of the Trinity to support Constantine and his quest, bringing the mortal general to the attention of his lover. He was unable to regain Michael's complete attention and, once the New Rome was founded in the fourth century AD, he tried to take the largest part of it for himself in retribution. He was the founder and leader of the Antonian Ventrue of Constantinople. Despite having a low opinion of the Followers of Set, he accepted the introduction of the Children of Judas, mainly to ingratiate himself to Michael.
The Dream prospered for centuries, with Michael delicately playing off his lovers against one another to maintain equilibrium in the Trinity. Antonius used the Thracian Justinian as his puppet to widen the influence of the Trinity, until Justinian died and his plans collapsed with him, further leading to the defection of his former pawn Narses. When Michael presented Symeon and Gesu to his lovers as gifts, Antonius was pleased and allowed his future progeny, Symeon, to intermingle with his brood.
When Symeon, however, was embraced by his brother, instead, Antonius rage against the Tzimisce had reached a breaking point. He supported the ascension of Leo III in 717 and initiated the Iconoclast Movement against the blood religions supervised by the Dracon. Seeking to create a much stronger version of the Sixth Tradition, resembling the Masquerade of the Modern Nights, he sought to eradicate all hints of Cainite existence in Constantinople.
The Dracon was the chief target of his ire, but his call for secrecy and hiding also alienated him from his favourite childe, Septima Dominica. He was described by the Dracon as the incarnation of solidity, permanence, unyielding, unbending, the bedrock foundation, the strength of mountains. By that same token, he was said to be not only solid but hard, uncompassionate, not only unyielding but unchanging, the enemy of change, who preferred stasis except when violent change served him better. Not only strong, but vicious in his strength, cruel when his protection was rejected, or not wanted.
The Iconoclast struggles, in both the mortal and vampiric spheres, eventually became so extreme that they led to Antonius' destruction by the hands of Caius in 796. Antonius' death was mourned by both Michael and the Dracon and caused the Dream to become dysfunctional, leading to Michael's growing insanity and the Dracon abandoning the city.