Ceoris

Ceoris was the primary chantry of the Tremere for centuries, both before and after they were transformed into vampires. The chantry was founded by Tremere himself in Transylvania, during the time when the Tremere were still the mortal mages of House Tremere. The foundation of the chantry, and the bloody events that followed, were subtly influenced by contact with two mysterious spiritual entities, known as Root of All and The Stars Above. Ceoris was the site of Goratrix's research that led him to perform the ritual that transformed Tremere and the original Council of Seven into vampires, and was the haven of Tremere and Etrius for centuries to follow. It served as their bastion against the Tzimisce during the Omen War, and was the birthplace of the Gargoyles and other Thaumaturgical innovations. During the Renaissance, the Gargoyles rose up against their masters, slaying many Tremere and all but razing the chantry. In the aftermath of the Gargoyle Revolt, the Tremere abandoned Ceoris, relocating their seat of power to Etrius' chantry in Vienna.

Note
In Ars Magica, House Tremere's primary covenant is called Coeris.