Caligula, born Gaius Julius Caesar Augustus Germanicus (31 August AD 12 – 24 January AD 41) was Roman emperor from AD 37–41.  Caligula (meaning 'little soldier's boot', or 'little boots') was born to the most powerful house in Rome: The Julio-Claudian dynasty.  Young Gaius was nicknamed "Caligula" by his father's soldiers while accompanying him during his campaigns in Germania. Caligula's biological father was Germanicus (The brother of Claudius I); he was the great-nephew and adopted son of Emperor Tiberius.
          Caligula's father and Claudius' brother Germanicus died at Antioch in AD 19.  His wife Agrippina the Elder returned with Caligula and his five siblings to Rome, where she engaged in a life and death feud with Tiberius; the ruler of the Roman Empire.  Her conflict with Tiberius was an extreme example of cultural naivety most likely the result of being an aristocrat that was married, and the co-parent of the extremely popular Germanicus.  Her battle with the supreme leader of the most powerful empire on Earth, save, possibly, that of China, lead to the death of every member of her family; every member but for Caligula.
          Caligula was isolated from these deadly machinations due to his extremely hedonistic life style.  Hedonism was something he had in common with Tiberius.  Tiberius offered him an invitation to join him in AD 31 on the island of Capri; where Tiberius had been sequestered for five years.  This was during the time that Sejanus was making his move to isolate Tiberius, and sieze control of the Empire.
          With the death of Tiberius in AD 37, Caligula succeeded his grand uncle and adoptive grandfather as emperor.
          There are few surviving sources about the reign of Emperor Caligula.  Critical thought would lead historians to view the description of Calugula as a noble and moderate ruler during the firstseveral months of his reign as the result of it being safe to do so.  As time passed, descriptions and comments on Caligula and his conduct centered on his more extreme conduct, and how they threatened the survival of those who had a great deal to loose.  I doubt if the common citizens in the street were very concerned that they would be loosing the little they had.
          While the reliability of historical sources is questionable, it is known that Caligula spent a great deal of resources securing the personal power of the emperor.  However, he did construct, incontrast to his luxurious dwellings,  two aqueducts: the Anio Novus and the Aqua Claudia.  He expanded the empire when he annexed the Kingdom of Mauretania, and making it a province of Rome.
           In early AD 41, Caligula was assassinated as a result of a conspiracy by officers of the Praetorian Guard, senators, and courtiers.  The conspirators' used the opportunity to restore the Roman Republic, but were uterly unsuccessful.  A very comical part of the BBC series was the moment that the players in the military, and, more importantly, the Praetorian Guard realized that they needed an emperor to secure their jobs; they declared Caligula's uncle, Claudius, the next Roman emperor.
          Whether Caligula was a crazy emperor who damaged the empire by setting standards for extremes and indulgences rather than rule and reason is easily ignored with even a superficial reading of the history to follow.  He did not.  The ascent of the crazy ruler existed before his reign, and has continued to the present day.  It is unlikely to change.  Brace yourself.
          The Claudio-Julian family supplied Rome with two more emperors; one crazy, the other not so much.

          Like all emperors, kings, prime ministers, presidents, and dictators, Caligula minted coins that were designed to increase his importance, status, and power. He did this by connected himself to his ancestors, religious groups, gods and goddesses, and the most significant people in Roman history.
          Below is a coin honoring Caligula's relation to his father Germanicus.

          Another example of Caligula's effort to absorb status by drawing a relationship, or better a connection to Agrippa (Marcus Vipsanius Agrippa) who was not an aristocrat or patrician, but was a hero in the minds of Romans. Agrippa was the close friend of Augustus, and his general during their victory over Mark Antony at the Battle of Actium September 2, 31 BC.

          Mark Antony was a pariah in the minds of most Romans.  He was a traitor to Roman values and virtues.
          Caligula was born the same year that Agrippa died; 12 AD. This probably didn't play in his effort to associate himself with Agrippa, however, Agrippa's winning the Battle of Actium and forcing Antony and Cleopatra to rush back to Egypt was a message the coin below suggests strongly.  The Battle of Actium was a naval battle, and Neptune is featured on this coin.
          Associating himself with Octavian and Aggripa, and separating himself from Antony was much more significant than the mere winning of a battle.  By associating himself with Aggripa, and thereby adding glue to his bond with his ancestor Augustus, Caligula make a statement of piety.
          Piety was arguably the most important virtue and value in the Roman Empire. To be pius was to be a model Roman man or woman. When Mark Antony married Cleopatra in 36 BC, but didn't divorce Octavia until 32 BC, he was seen to have rejected Roman tradition, law, and respect for piety, and at the same time slap Octavian upside the face.  Piety meant duty, religiosity, loyalty, devotion, and charity. Antony was seen to have adopted the gods and goddesses of Egypt.

          Whether he actually appointed the horse Incatatus to the senate, believed himself to be a god, had sex with his sister, or were merely the writings of people who dipped pen to ink when it was safe, and wonderful to do so, it is clear that Caligula was unique, interesting from our perspective, and the brick and mortor of may fine books and movies.