100 Mistakes That Changed History: Backfires and Blunders That Collapsed Empires, Crashed Economies, and Altered the Course of Our World

18. TAKING THE EASY WAY

When the Roman emperor Diocletian decided to divide his realm into an eastern empire and a western empire, he did so in order that his forty-four provinces might be more easily governed. He obviously had never read anything on Roman history; otherwise he would have known that every time the empire had been divided to make it more manageable, it resulted only in civil war or invasion. But it is unlikely that Diocletian knew his history, because he was illiterate. The requirements for being emperor had vastly deteriorated since the time of Marcus Aurelius. Diocletian proved his ability as a military commander, but his inability to learn from the errors of his predecessors would cost his citizens greatly, eventually lead to civil war, and hasten the collapse of Roman rule in the western half of the empire.

Diocletian had grown anxious about the growing number of barbarian invasions in Gaul. He had already created a mobile army to deal with the situation, but he decided that the best way to handle it would be to have a stronger power base in the west. He appointed his close friend Maximian as his co-emperor to rule from Gaul while Diocletian would rule from Nicomedia in Asia Minor. In doing this, he set up a structure that was supposed to ensure peaceful succession to each office. The two emperors would be called Augustus, and they were to pick a successor who was not a son, no matter how competent the son might be. Diocletian then chose two co-regents, who would be called Caesar. Galarius became the Caesar in the east and heir to Diocletian, while Constantius ruled with Maximian as the Caesar in the west. With separate leaders, separate armies, and even separate tax collectors, the Roman empire became in effect two empires.

There was still the risk that family ties would interfere with his plans to ensure that the Caesar would become the Augustus. To keep the family ambitions of each man in the tetrarchy at bay, Diocletian “requested” that their sons live in his court. One of these sons was Constantine, the son of Constantius. Although the sons were virtually hostages, Diocletian treated them well. Despite being illiterate, he gave the boys the best education and even made sure they learned Greek. Constantine eventually became one of Diocletian’s most trusted soldiers, but the Augustus grew uneasy. The emperor had issued the Great Persecution against the Christians and, although Constantine himself did not fall into the sect, his mother did. As one of the emperor’s top men, he had witnessed many atrocities under the new edict. When the aging emperor fell ill, he failed to include Constantine in the exchange of power. Constantine realized for the first time what his position had been. He was a mere hostage and was also expendable.

Constantine fled to Boulogne in Gaul to meet his father. His arrival could not have been better timed. Constantius then ruled over Spain, Gaul, and Britain. In Britain, his father faced an uprising of the always unruly Picts. So father and son went to Britain together. Constantine soon won the favor of his father’s army by leading them in defeating the Picts. When his father died in 306, the army recognized Constantine as their new leader. They chose wisely. Not long after, when the Barbarian Franks invaded Gaul, Constantine led the cavalry charge against them and defeated them. Constantine celebrated this victory with a triumph that marched through the streets of Trier. The citizens loved him.

While Constantine was gaining support in Gaul and Britain, a usurper rose to power in Italy and North Africa. Maxentius had taken over by promising lower taxes and free grain. (He is not to be confused with Maximian, who was one of the original tetrarchy.) When the people realized the promises he made would be delivered only to the wealthy, they began to revolt. Riots broke out all over Rome. Constantine saw it as his duty to overthrow the upstart and restore order. He formed an alliance with Licinius, who now controlled the eastern half of the empire. Together they rallied their troops to fight their fellow Romans just outside Rome. This was exactly what Diocletian had sought to avoid, civil war.

On the eve of battle, Constantine is said to have seen the Greek letters chi and rho appear in the sky (the first two letters of the word Christ). He heard a voice say, “Under this, you will conquer.” Constantine had witnessed the resilience of the Christians when they were undergoing persecution by Diocletian. Rather than discouraging the faith, the number of Christians had grown at an enormous rate. It is possible that Constantine saw a people whom he could use to help win the empire. Whether it was motivated by politics or a spiritual awakening, Constantine ordered his men to paint the Christian symbol on their shields. Together the forces of Constantine defeated Maxentius at the Milvian Bridge. Constantine had the head of his enemy paraded around the empire. With this single victory, Constantine became the sole ruler of the western empire.

Despite Constantine’s victory, there was no peace. The alliance Constantine formed with Licinius broke down. As the conflict between the two rulers grew more tense, Licinius found a way to strike out against his nemesis in the west. Like Diocletian before him, he persecuted the very sect of people whom Constantine had claimed as own: the Christians. The persecutions were not founded on religious divergence; they were purely political. Licinius saw the Christians as Constantine’s people. For nine more years, tensions between the east and west worsened until the antagonism came to a head. Once again the country was on the verge of civil war.

The battle that would decide who would take possession of all the vast expanses of the Roman Empire took place at Chrysopolis in 324. Constantine defeated Licinius’ army and became the sole emperor. Because Constantine’s sister, who was married to Licinius through the previous alliance, had begged for mercy for her husband, Constantine spared him, at least for a while. But he later had his enemy killed while imprisoned.

With his enemies annihilated, Constantine could focus on what meant the most to him: his new Christian empire. Because the brunt of economic and military activity in the empire took place in the northeast, he decided to establish a new capital on the site of the former Greek city of Byzantion. He chose the location because of its great strategic advantage. It lay near the Mediterranean Sea and the Black Sea and allowed access to Anatolia and the Danube. He changed the city’s name to Constantinople. The city became his obsession. He focused all of his resources on building roads, elaborate cathedrals, schools, and more secure walls. He transformed the city into the jewel of the east. It became a center of knowledge, wealth, and prosperity. It was cosmopolitan. It was Christian. But, most of all, it was Greek. The split Diocletian began was complete.

After Constantine’s death, his capital city continued to flourish. But the Latin-speaking west did not. The empire was politically and culturally split due to language differences, philosophical differences, and eventually religious differences. Power struggles developed between the pope in Rome and the patriarch in Constantinople. These would eventually lead to the Great Schism in the Church. By 395, the empire was officially split yet again. Without the support of the east, the west fell prey to barbarian invasions and was lost in the sixth century. This is often seen as the end of the Roman empire. But it was not until 1453, when the Turks took Constantinople, that the last and long separate eastern half of the empire truly ceased to exist.

Once Diocletian split the Roman empire, it changed everything. The rich east even diverted barbarian invasions toward the west. Diocletian’s dream of an efficient and divided but cooperative empire was a nightmare that doomed the western half of the Roman empire. Had the empire stayed united, Rome might have had the resources and strength to survive for centuries more, like Byzantium did. At first it was more efficient for Diocletian to divide up the empire. But for millions, the split was a mistake that doomed them to a millennium of darkness.