The Good Emperors ruled in the second century, as we just saw. Things did not go so well in the third century, as emperors came and went quickly. True, there were four who ruled for over ten years each, which suggests stability, but there were perhaps seventeen who ruled for less than two years. To learn why they did not rule longer, use Google to visit sites listing and discussing the assassination of Roman Emperors. What the Praetorian Guard had the power to do, they could also undo, and it was often thanks to them that men rose rapidly to the highest office and were as rapidly removed from it in the only way possible.
The Porta San Sebastiano allows but protects the passage of the Via Appia through the Aurelian Walls. No gate and walls were needed to protect Rome for centuries: her armies did the job. But defense had already begun to be an issue in the third century, when these walls were first built.
I will focus podcasts not on this period of instability but on Constantine and his century, the fourth. This was not a century with rapid turnover at the top: Constantine ruled for thirty years, longer than any emperor except Augustus; his son Constantinus II ruled for twenty; and five other emperors in the fourth century ruled for over ten years each.
Notwithstanding this evidence of stability at the top, it was still a century of warfare and dramatic change. In order to rule for thirty years as Emperor, Constantine first had to seize the position: he had no claim to it but what his armies could provide. He used these armies in a series of battles that saw him marching always eastward from the extreme western part of the Empire, in Wales. He defeated his first imperial rival in three major battles in 314, all in Italy, and then he spent the next decade attacking his second imperial rival in battles that mapped his march eastward. His culminating and final victory to unify the entire empire under himself came in Asia, just east of Byzantium, soon to be renamed Constantinople.
As Constantine was uniting the Empire under himself, he also made Christianity legal and, then, supported it and even integrated the Christian bishops into his regime. His successors took his pro-Christian policies further, and by the end of the century, it was the dominant religion of the entire Roman Empire (and beyond). Paganism was now illegal and on the path to extinction. Coinciding with the dual triumphs of Constantine and Christianity, Rome lost its privileged position as the capital city of the Empire, for Constantine also renamed Byzantium “Constantinople,” and made it the new capital of the Roman Empire. For this and other reasons, Rome’s population and wealth began to decline precipitously. As invasions by the Goths and the Vandals showed in the next century, the end of the western Roman Empire was near.
Head of Constantine the Great, now in the Capitoline Museums (My photo)
Our main visits with regard to the events just mentioned will be to the Arch of Constantine adjacent to the Colosseum, the Room of Constantine in the Vatican Museums, the cycle of frescoes in the Chapel of Sylvester in the Basilica of Santi Quattro Coronati, and several statues or statue parts of Constantine, especially the equestrian statue by Gianlorenzo Bernini in the narthex of St. Peter’s.