Bay Area. Later, Caligula joins forces with Commodus and Tarquin to destroy Camp Jupiter but ends up being killed by Frank who apparently sacrifices himself to destroy the emperor by burning up his firewood representing Frank's lifeline. To much surprise, Frank survives the experience and is left with his life no longer tied to the wood. King Tarquin - One of the three main antagonists in The Tyrant's Tomb alongside Commodus and Caligula. Tarquin is the last king of Rome and is depicted as a zombie. He participated in the Battle of San Francisco Bay where he targeted the Sibylline Books. Tarquin was killed by Hazel and Diana who stabbed him in the chest and shot him in the head with an arrow respectively. Greek-Roman deities Twelve Olympians Though not all the gods who appear in Rick Riordan's novels are truly Olympians (that is, gods who live on Mount Olympus), all Greek and Roman gods are generally considered to be a subset of the Twelve Olympians. As such, most characters in the series refer to these immortals generally as the "Olympian gods", to distinguish them from the Greco-Roman primordial gods and Titans. Zeus/Jupiter – The king of the gods and the most powerful Olympian by far, Zeus is most prominent in The Lightning Thief but has several roles throughout the rest of Percy Jackson & the Olympians. Zeus is shown prominently throughout the series to be extremely narcissistic, paranoid and hypocritical. In The Lost Hero, under the influence of Khione, Zeus forbids contact between gods and mortals and closes off Olympus (against the influence of Khione), although he indirectly helps the protagonists several times on their quests. As the primary Olympian god, his demigod children reside in Camp Half-Blood's biggest cabin, Cabin 1, although there is only one person who resides there at the end of The Heroes of Olympus: Jason. In the film adaptation, Zeus is played by Sean Bean. Lance Reddick will portray Zeus in the TV show. Hera/Juno – The queen of the gods who plays a role in The Titan's Curse, by helping Percy and the others on their quest in The Battle of the Labyrinth. As Juno in The Lost Hero, she is kidnapped by Gaea, and contacts Jason Grace to rescue her. Previously, as Juno, she had sneaked out of Olympus and switched Percy and Jason to try to unite the Roman and Greek