Caius

Caius is a vampire.

History
Caius was born around 1300 BC, and at some point became a vampire. He was born at least a century before Aro and was transformed into a vampire in his late 40s.

He met Athenodora after running afoul of the Romanian coven, and they began traveling together as a bonded pair, with her later becoming his wife. When they came across Aro, he was quite taken of the vampire's ambitious but long-ranged plans of domination. By the time they met, Aro had already formed a coven with a talented vampire named Marcus. Caius was immediately attracted to the idea of joining forces with the gifted vampires. Though Caius had no psychic gift, Aro was drawn to his ambition and passionate capacity to hate; which was a great potential for manipulation in wha tcould be both a weakness and a strength.

Aro's sister Didyme joined them quickly afterwards; and later Aro's wife, Sulpicia. Aro and Caius were in agreement after Didyme's death had devastated Marcus that the wives must be protected at all costs. By bringing more vampires into the Volturi as subordinates, they brought about his ultimate goal: a war against the Romanian coven. After the Romanians were mostly destroyed, Caius became satisfied to spend his time punishing offenders of Aro's law due to Chelsea's power that kept him bound to the coven.

Around 10 AD, he was nearly killed in a fight with a werewolf, which prompted him to hunt them to near extinction. He also took part in the extermination of the immortal children and cleaning up after the Southern vampire wars, making sure that newborn armies and their creators were destroyed, but when he felt bored, he would have Corin use her power to make him happy.

Family Members

 * Athenodora (wife)

Source

 * Twilight Saga Wiki: Caius