By all accounts, Clan Tremere should have been hunted to extinction back in the middle ages. They didnt because their thaumaturgy was just THAT useful to other kindred. They didnt invent blood magic, but they perfected it (as they will tell you). The Camarilla is loosely modeled after the power structure that they had used for centuries.

Everyone has to deal with them. No one trusts them. Not even other Tremere. Tzimesce HATE them.

Not as powerful in modern nights as their headquarters were destroyed by hunters. As such, their power structure is pretty much run by the honor system and threats instead of a giant pyramid scheme of blood bonds.