What kind of ruler gains absolute power over the Roman world and then gives it up to tend a vegetable garden? This deep dive explores Diocletian, a low-born Dalmatian cavalry commander who took power amid the crisis of the third century and rebuilt a collapsing empire through sweeping, often suffocating reforms.

We cover his dramatic seizure of power after Numerian’s corpse was discovered in a curtained coach, the Tetrarchy that split rule among four emperors under Jupiter and Hercules, a vastly expanded bureaucracy and army, the failed Edict on Maximum Prices, and laws tying people to land and trade. We also examine the Great Persecution of Christians, his 305 AD abdication, and the civil wars that followed.

• Executing the prefect Aper in front of the army to claim the throne in 284 AD
• How the Tetrarchy and the Jovius and Herculius titles tried to stop usurpers
• Why the Edict on Maximum Prices caused shortages and black markets
• The failed sacrifice and pressure from Galerius that led to the Great Persecution
• Bypassing Constantine and Maxentius, and his famous reply about the cabbages at Split