Elagabalus (s/), also known as Heliogabalus (Latin: Marcus Aurelius Antoninus Augustus; c. 203 – 11 March 222), was Roman emperor from 218 to 222. A member of the Severan dynasty, he was Syrian, the second son of Julia Soaemias and Sextus Varius Marcellus. In his early youth he served the god Elagabalus as a priest in Emesa, the hometown of his mother's family. As a private citizen, he was probably named Sextus Varius Avitus Bassianus. Upon becoming emperor he took the name Marcus Aurelius Antoninus Augustus. He was called Elagabalus only after his death.
In 217, the emperor Caracalla was assassinated and replaced by his Praetorian prefect, Marcus Opellius Macrinus. Caracalla's maternal aunt, Julia Maesa, successfully instigated a revolt among the Third Legion to have her eldest grandson (and Caracalla's cousin), Elagabalus, declared emperor in his place. Macrinus was defeated on 8 June 218 at the Battle of Antioch. Elagabalus, barely 15 years old, became emperor, initiating a reign remembered mainly for sex scandals and religious controversy.
Later historians suggest Elagabalus showed a disregard for Roman religious traditions and sexual taboos. He replaced the traditional head of the Roman pantheon, Jupiter, with the deity Elagabalus, of whom he had been high priest. He forced leading members of Rome's government to participate in religious rites celebrating this deity, over which he personally presided. Elagabalus was supposedly "married" as many as five times, lavishing favours on male courtiers popularly thought to have been his lovers, and was reported to have prostituted himself in the imperial palace. His behavior estranged the Praetorian Guard, the Senate, and the common people alike. Amidst growing opposition, Elagabalus, just 18 years old, was assassinated and replaced by his cousin Severus Alexander on 11 March 222, who ruled for 13 years before his own assassination, which marked the epoch event for the Crisis of the Third Century. The assassination plot against Elagabalus was devised by his grandmother, Julia Maesa, and carried out by disaffected members of the Praetorian Guard.
Elagabalus developed a reputation among his contemporaries for extreme eccentricity, decadence, and zealotry. This tradition has persisted, and with writers of the early modern age he suffers one of the worst reputations among Roman emperors. Edward Gibbon, for example, wrote that Elagabalus "abandoned himself to the grossest pleasures and ungoverned fury". According to Barthold Georg Niebuhr, "The name Elagabalus is branded in history above all others" because of his "unspeakably disgusting life".
The deity Elagabalus was initially venerated at Emesa. This form of the god's name is a Latinized version of the Syrian Ilāh hag-Gabal, which derives from Ilāh (a Semitic word for "god") and gabal (an Arabic word for "mountain"), resulting in "the God of the Mountain," the Emesene manifestation of the deity.
The cult of the deity spread to other parts of the Roman Empire in the 2nd century; a dedication has been found as far away as Woerden (Netherlands), near the Roman limes. The god was later imported and assimilated with the Roman sun god known as Sol Indiges in republican times and as Sol Invictus during the second and third centuries CE. In Greek the sun god is Helios, hence "Heliogabalus", a hybrid conjunction of "Helios" and "Elagabalus".