Volturi

"The Volturi aren't supposed to be the villains, the way they seem to you. They are the foundation of our peace and civilization."

- Edward Cullen about the Volturi.

The Volturi (also known as the Volturi Coven) are a civilized coven of vampires, the largest and most powerful organization in the series, and enforce the  laws  of the vampire world.

The equivalent of royalty in the vampire world, the Volturi consists of 5 core members: Aro,  Caius ,  Marcus , Aro's wife  Sulpicia , and Caius's wife  Athenodora. Marcus's wife (and Aro's sister), Didyme, was also a member before she was killed by her brother. Aside from these head members, it also consists of a collection of powerfully imposing vampires, known as the Volturi guard, three of which are most powerful.