In 58 BC, Julius Caesar embarked on a campaign that transformed Gaul—modern France, Belgium, and beyond—into a Roman province . What propelled this conquest? Strategic fears had long haunted Rome, from the Gallic sack of the 390s BC to Germanic pressures across the Rhine. Economic prospects tantalized as well. Yet Caesar’s ambition loomed largest, and his victories reshaped what had been a frontier into the Roman Empire’s heartland.

Rome’s early Republic leaned on its legions, with no real navy to speak of—until Carthage, a sea-dominating empire, sparked the First Punic War in 264 BC. Exposed and outmatched, Rome turned the tide in 261 BC, reverse-engineering a captured Carthaginian ship to craft a fleet of quinqueremes. Armed with ingenious corvus boarding bridges, Rome's new navy stunned Carthage, and launched Rome as a Mediterranean powerhouse. How did land-locked Rome master the seas?

Aurelian—a gritty Balkan soldier—seized a crumbling Roman Empire in AD 270. His five-year reign still stuns: how did he crush Germanic hordes, topple Zenobia’s Palmyrene Empire and reunite the Gallic Empire under Roman rule? But Aurelian was more than a conqueror. He constructed miles of walls around Rome, and erected a massive temple to Sol Invictus--god of the unconquered sun.

As a lethal plague tore through Rome, Persian king Sapor I struck the Empire’s east, capturing Emperor Valerian—a staunch senator and fierce Christian persecutor—after his bold counterattack failed. Internal strife and external foes shattered Rome into three warring realms: the Gallic and Palmyrene Empires rose amidst the chaos. Would the third century witness Rome’s doom?

In AD 249, the Plague of Cyprian swept through the Roman Empire. Named after Cyprian of Carthage, who vividly described its horrors, this plague led to loss of life and increased imperial destabilization during an already turbulent time. Accounts from Cyprian and Dionysius of Alexandria highlight the plague's severity, noting it seemed to threaten the very existence of humanity. At the same time, the emperor Trajan Decius issued an edict requiring universal sacrifice to Roman gods across the entire Empire, putting Christians in the crosshairs. How did the Christian community respond to both the plague and the persecution under Decius?

The Crisis of the Third Century began with the assassination of Severus Alexander, leading to Maximinus Thrax's brief and unpopular rule. Maximinus treated Rome like his own personal piggy bank--looting everything from senatorial estates, to local funds for festivals and celebrations. he was assinated in AD 238, also known as the Year of the Six Emperors. By the end of that year, a pre-teen boy sat alone on the throne. It was his task to try to save a beleaguered and besieged Roman Empire.

The Roman monetary system--one of the worlds most stable and trusted monetary systems for nearly 500 years, seems to have collapsed in the third century AD. Rapid debasements made Roman silver coins nearly valueless. This economic instability may have prompted inhabitants of the Roman Empire to stop using currency in some regions. In just the AD 270s alone, prices rose by around 1,000%. What happened to Roman currency and could anything have been done differently?

Was the third century AD a period of crisis or transformation? The prevalence of war, economic strain and demographic collapse certainly seems compelling. And yet, this same period could be viewed as a transformation where Rome adapted, with power shifting from traditional elites to military figures, and where cultural, religious, and social structures evolved. Was the constant warfare a sign of an empire's decline, or was it forging a new and more sustainable system?

Cassius Dio, a Roman historian and senator, seems to have foreseen the tumultuous times the Roman Empire was about to experience in the Crisis of the Third Century. His proposed reforms come to us through the lens of his famous debate between Agrippa and Maecenas in his epic history of Rome. Dio envisioned a stable, centralized Roman Empire, including a professional standing army, fiscal responsibility and a nuanced balance of power between the Senate and the Emperor. I analyze these prescient warnings and discuss the extent to which they might have been successful.

Alexander Severus, Roman Emperor from 222 to 235 AD, ascended to power under the guardianship of his mother and grandmother. He offered a serious foreign policy--aimed at stabilizing increasingly fragile borders to both the north and east of the Empire. But the Crisis of the Third Century was looming, and Rome's legions apparently no longer wished to have peace--preferring instead the profits of foreign and civil wars.