Final answer:
The Historia Augusta contains biographies of various significant figures in Roman history, including emperors and non-emperors. Non-emperors like Antoninus Pius and Marcus Aurelius had significant contributions to Roman Empire, while infamous emperors like Caligula and Nero are remembered for their tyrannical reigns. Julius Caesar and Augustus, while pivotal figures, were not technically emperors, and Diocletian and Constantine the Great introduced significant changes to the structure and religion of the empire respectively.
Step-by-step explanation:
The Historia Augusta is a collection of biographies of Roman emperors and other noteworthy figures. Non-emperors covered in the Historia Augusta include figures such as Antoninus Pius and Marcus Aurelius, who were two of the five good emperors of the Roman Empire. Antoninus Pius ruled from 138 to 161 CE and his reign is chiefly noted for his just and expert handling of Roman legal and administrative machinery. Marcus Aurelius, his adopted son and successor, is renowned as a philosopher king whose personal philosophical writings, known as Meditations, offer insight into Roman Stoic philosophy.
Contrarily, other figures like Caligula and Nero were in fact Emperor's but with notorious reputations. Caligula ruled from 37 to 41 CE and is remembered for his cruel and tyrannical behavior. Nero's reign from 54 to 68 CE was marked by several events of note, including the Great Fire of Rome and heavy persecution of Christians.
Roman leaders like Julius Caesar and Augustus, while mentioned in historical documents, were not technically emperors. Julius Caesar was a famous Roman general who played a crucial role in transforming the Roman Republic into the Roman Empire. Augustus, also known as Octavian, inherited Caesar's power and became the first emperor of Rome.
Lastly, figures like Constantine the Great and Diocletian were emperors. Diocletian introduced a tetrarchy, or rule by four, dividing the empire into east and west portions to better handle external threats and internal pressures. Constantine the Great is known for establishing the city of Constantinople and for his conversion to Christianity, paving the way for the Christianization of the Roman Empire.
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