In the early 3rd century AD, the Roman Empire teetered on the edge of an epic fall. On March 8, 217, the despised and ruthless Emperor Caracalla stopped to relieve himself against a roadside tree during a long overland ride, insisting on some privacy as he did so. In his moment of vulnerability, one of his guards, Julius Martialis, assassinated the Emperor with a single thrust of a dagger. Martialis did not survive his victim for long, as one of the Emperor's other bodyguards, a Scythian, immediately shot the assassin dead.

However, Caracalla, while reviled by the general public, enjoyed great popularity with the soldiers, and at the time the Roman army wielded a great amount of political power. Caracalla's head of the military, Adventus, declined the position of Emperor, and instead encouraged the promotion of Opellius Macrinus, a prefect of the Praetorian Guard who controlled the Empire's civil and financial affairs. Macrinus, a gifted businessman by nature who had trouble understanding the military, and a foreigner by birth who rarely left Syria, ascended to the throne but quickly fell out of favor with the Roman army. Despite Macrinus's skill in financial matters, he was reluctant to engage in battle, and the soldiers disrespected him for that reason; before long they began looking around for a worthy successor to Caracalla.

Their choice was perhaps the most enigmatic Roman Emperor in history. Varius Avitus Bassianus, the son of Caracalla's Syrian cousin, was fourteen years old, and was by all accounts a capricious, prancing homosexual who worshipped El-Gabal, the Syrian sun god, and so under normal circumstances would probably not be the favored son of the Roman military elite. However, Avitus's grandmother Julia Maesa, who was also Caracalla's aunt, renamed the boy Marcus Aurelius Antoninus, and began spreading the false news that he was Caracalla's illegitimate son, despite the fact that that would make him the union of two first cousins, which was grounds for exclusion. Soldiers still loyal to Caracalla, commanded by Avitus's eunuch Gallys, who had absolutely no battlefield experience, backed the young boy, and at the Battle of Antioch on June 8, 218, they defeated an army of veteran Praetorians under Macrinus's command after the "False Antoninus" charged boldly into the enemy ranks, swinging wildly and inspiring his men to follow. Macrinus and his son were both caught and immediately executed.

The reign of "Antoninus" was bizarre and unrestrained. He married five times in four years, once to a woman whose husband was one of the many people he had killed upon taking office, and in between wives he had defiled a Vestal Virgin with the intention of making godlike children. He had the palace statue of Jupiter decapitated and replaced with the head of El-Gabal, and he circumsized himself as a display of purity. He performed rites and staged parades dedicated to his alien deity in public, all of which was seen as blasphemous by the public. He had a habit of standing naked in a palace doorway, propositioning passers-by and prostituting himself to them. He cross-dressed virtually every day, and as a woman he "married" a slave named Hierocles, referring to himself as "his Queen".

None of this sat well with the army who had installed him on the throne. In March of 222, Julia Maesa, the same grandmother that had installed him, decided she would replace him with his younger cousin Severus Alexander. In response, Antoninus stripped Alexander of his titles, a riot broke out, and the Praetorian Guard called for Antoninus. Suddenly, the Emperor realized his time was up, and he—still only 18 years old and slight of stature—climbed inside a chest with the hopes of escaping. He was, however, found, and the Praetorians cut off his and his mother's heads, and threw their bodies into the Tiber River.

After his death, Marcus Aurelius Antoninus became known either as Elagabulus—the Latinized version of his Syrian deity's name—or Tiberinus, in mocking memory of the river into which his corpse was thrown. He was so hated that he was issued a damnatio memoriae, the results of which were that his name and likeness were completely erased from all records, accounts, and statues, in an attempt to eliminate entirely from history.

Links and Sources:
Roman History, Volume IX, by Cassius Dio.
The Historia Augusta, published in the Loeb Classical Library, 1924.
The Decline and Fall of the Roman Empire, by Edward W. Gibbon.
Source pages for photos of busts of Caracalla, Macrinus, and Elagabalus.