Inconnu
Supposedly the oldest known sect, the origin, goals and even very existence of this group are largely unknown to the supernatural population at large. The Inconnu has been linked variously to Infernalism, Golconda, Saulot and a host of other conspiracies. Several cities in the World of Darkness have Inconnu monitors, mysterious elder vampires who do little, other than watch the events of their chosen city.
The official storyline for V:TM ended before much was revealed regarding the Inconnu. They were the last secret left unanswered. The Inconnu were elders (Methuselahs) who wished to withdraw from Kindred politics (the Jyhad), kindred seeking Golconda, and hunted clans and bloodlines like the Salubri. All have sworn an oath of Autarkis, the vampires who have turned their back on the Jyhad, refusing to serve a sect, Camarilla or Sabbat, or associate with their Clan outside of the Inconnu.
One Gehenna scenario offered the possible answer that the Inconnu elders were antediluvians besides the 13 who, for the most part, never sired and were loyal to Lilith. In the scenario they help Lilith defeat Caine.
Read more about this topic: Masquerade Society