Caligula, Claudius, and Nero (in that order) are the last three emperors of the Julio-Claudian Dynasty. Popular history tends to remember all three of them as wicked tyrants and, if the ancient sources are to be believed, with good reason. Seeing as many of the accounts of their rule were written by their rivals or by later politicians who needed to justify their reign, however, the testimony of primary sources is routinely questioned by historians.

Augustus Caesar was the first emperor of the Roman Empire and does not belong in the list of the so-called Five Good Emperors. The Five Good Emperors were (in order): Nerva, Trajan, Hadrian, Antoninus Pius, and Marcus Aurelius. These emperors have generally been renowned by historians for their skilled leadership and wise decision making.

The Praetorian Guard was created by Rome’s first emperor, Augustus Caesar. The purpose of the Praetorian Guard was to provide a regiment of trained, loyal soldiers to protect the emperor’s wellbeing. The Praetorian Guard soon grew in power and became influential in legitimizing the rule of later emperors.

The Julio-Claudian Dynasty refers to the first five emperors of the Roman Empire. It begins with the reign of Augustus Caesar in 27 BCE and ends with the reign of Nero in 44 CE. Of these rulers, only Titus is not a member of the Julio-Claudian Dynasty. Titus was the emperor during the Great Fire of Rome in 80 CE, and was a member of the Flavian Dynasty.

Augustus Caesar was the first emperor of the Roman Empire. He came to power in 31 BCE (as Octavian) and was crowned Emperor Augustus Caesar in 27 BCE. His reign marks the beginning of the Pax Romana — a two centuries long period of prolonged peace and prosperity in the Roman Empire. He created a standing army and introduced a pension for Roman soldiers (two reforms which greatly improved the fighting capacity of the Roman Empire). He was not, however, assassinated by a group of noblemen (that was Julius Caesar).

Vespasian, who came to power at the end of the Year of Four Emperors, was the first Emperor of the Flavian Dynasty. He was also the first Emperor to be succeeded by one of his sons. Titus, who took power in 79 CE, was Vespasian’s son. Both Vespasian and his son Titus gained political prominence through the suppression of the Judean rebellion.

The four rulers who ruled during the Year of the Four Emperors are (in order): Galba, Otho, Vitellius, and Vespasian. The Year of the Four Emperors took place in 69 CE, after the death of Emperor Nero. It was a year of political turmoil and civil war in the Roman Empire. It ended with the rule of Emperor Vespasian, who ushered in the short reign of the Flavian Dynasty.

The Emperor Marcus Aurelius was the last emperor of the Pax Romana and was also the last of the so-called Five Good Emperors. The Pax Romana is the name given to a period of relative peace and prosperity that prevailed in the Roman Empire from the beginning of Augustus Caesar’s rule in 27 B.C.E. until the end of Marcus Aurelius’ rule in 180 CE.

Nero’s death in 68 CE brought to an end the rule of the Julio-Claudia Dynasty, which had begun with the reign of the first Roman Emperor, Augustus Caesar. Nero’s death also ushered in the Year of the Four Emperors. The year 69 CE witnessed the first civil war in Roman history since the conflict between Octavian and Mark Antony (which brought to an end the Roman Republic). The Year of the Four Emperors ended with the Emperor Vespasian taking control and ushering in the Flavian Dynasty.

The Praetorian Guard was first created in the early years of the reign of Rome’s first emperor, Augustus Caesar. The Praetorian Guard was created to serve as a regiment of trained bodyguards for the Roman Emperor. Initially, the power of the Praetorian Guard was limited, but their power slowly increased during the reign of Augustus Caesar and later emperors would come to depend heavily on the Praetorian Guard to both legitimize and protect their power.