Europe 41 AD: Reign of Caligula
When Tiberius died in 37 AD, the throne passed to his 24-year-old nephew Gaius Caesar, better known as Caligula. Despite his initial popularity, Caligula’s rule soon became arbitrary, cruel, and self-absorbed. He began pushing for his absolute power in Rome and, after abandoning Armenia and conducting a farcical military campaign against Germania and Britain, summarily executed the Client King of Mauretania, provoking a revolt in Africa. In early 41 AD, resentful of Caligula’s behavior, the Praetorian Guard assassinated him and proclaimed his uncle Claudius the new emperor—a sinister first in the history of the Empire.
36–42 AD Parthian Civil Wars of 36–42▲
Shortly after regaining his throne after the civil war of 36 AD, Artabanus II of Parthia had to face a rebellion in Seleucia, former capital of the Seleucids and a center of Greek aristocracy in the Parthia Empire. While attempting to deal with the revolt, Artabanus was overthrown by Cinnamus, a Parthian noble, and fled to Adiabene. The King of Adiabene negotiated Artabanus’ return to power, but the latter ruled for just over a year more before dying in 38 or 39 AD, leading to civil war between his sons. One son, Gotarzes, seized power and murdered his brother, another Artabanus, but was overthrown in turn by a third brother, Vardanes. Returning with Hyrcanian and Dahae support, Gotarzes then expelled Vardanes to Bactria. However, faced with intriguing nobles at home and in Armenia, the two brothers reluctantly agreed on peace, with Vardanes as shah. With the arrival of Vardanes back in Ctesiphon, the Parthians finally accepted the capitulation of Seleucia in 42.
28 Mar 37–24 Jan 41 AD Principate of Caligula▲
In March 37 AD the 24-year-old Gaius Caesar—remembered as “Caligula” (little boots) after the nickname his father Germanicus’ soldiers gave him—succeeded Tiberius as emperor of Rome. Although popular and moderate at first, Caligula became increasingly tyrannical and unrestrained after an illness brought him near death in October 37. Following his frequent insults and threats against the Senate and other major figures in Rome—and his contemplation of moving the capital to Alexandria, where he could be worshiped as a god—Caligula was assassinated by members of the Praetorian Guard in January 41 AD, after a reign of less than four years.
37–44 AD Reign of Herod Agrippa▲
In 37 AD Caligula made his friend, Herod Agrippa, client king of Batanaea and other Jewish territories which Tiberius had annexed to Syria. Two years later, Agrippa brought about the banishment of his uncle, Herod Antipas, and was granted Antipas’ domains of Galilee and Peraea. Agrippa reached the peak of his power in 41 AD when, after Caligula’s death, he supported Claudius and in return became ruler of a restored Kingdom of Judea. Agrippa’s realm lasted until his death three years later, upon which it was annexed back to the Roman Empire.
37 AD Caligula’s interference in Armenia▲
In 37 AD the Roman emperor Caligula undid Tiberius’ intervention in Armenia (35 AD) by ordering the arrest and imprisonment of King Mithridates, allowing Shah Artabanus II of Parthia to restore Orodes—Artabanus’ son and Mithridates’ old rival—to the Armenian throne. At about this time, Caligula made Cotys king of Lesser Armenia—the first mention of this kingdom as a Roman client state.
37–38? AD Caligula’s Commagene▲
When he gained power, Caligula granted Gaius Julius Antiochus, his friend and brother-in-law, the position of client king of Commagene, restoring that kingdom (Tiberius had annexed it after the death of Antiochus’ father in 17 AD). In addition to Commagene, the new king received Cilicia Tracheia and part of Lycaonia. However, Antiochus soon had a falling out with Caligula, who abruptly deposed him.
Sep 39–May 40 AD Caligula’s Northern Campaign▲
In 39 AD Caligula traveled north to prove his military skills against the Germans but encountered no action before deciding on an invasion of Britain the next year when Adminius, son of King Cunobeline of the Catuvellauni, sought his aid. It is believed Caligula built a lighthouse at Itius Portus (Boulogne?) but then canceled the campaign, allegedly ordering his assembled forces to collect seashells (musculi) as plunder (although soldier’s huts were also called musculi). Before returning to Rome, he supplemented the few prisoners he had captured with Gallic slaves disguised as Germans to accentuate his triumph.
40–44 AD Seizure of Mauretania▲
In 40 AD Caligula had King Ptolemy of Mauretania—who was visiting him at the time—arrested and executed; according to Suetonius, this was because a crowd admired Ptolemy’s purple cloak (the color was reserved for emperors). The Romans then took control of Mauretania, prompting Ptolemy’s former household slave Aedemon to lead a Berber revolt in the west. The rebellion would not be fully suppressed until 44 AD, three years after Caligula’s death.