Diocletian, architect of the Tetrarchy system that divided imperial rule among four men, stepped down from power in a formal ceremony, forcing his co-emperor Maximian to do the same on the same day in Milan. It marked the first time a Roman emperor voluntarily relinquished the throne rather than dying in office or being overthrown, retiring to grow cabbages at his palace in Split.
By 305 AD, Diocletian had ruled for two decades and reshaped the Roman Empire more thoroughly than any emperor since Augustus. He split the sprawling empire into four administrative zones under the Tetrarchy, reformed taxation, and launched the last great persecution of Christians. But chronic illness in his final years sapped his authority and his will to rule.
On March 18, 305, in a ceremony before his troops near Nicomedia, he removed his imperial purple robe and formally transferred power to his chosen successors. He compelled his reluctant co-augustus Maximian to do likewise in Milan the same day, a piece of remarkable long-distance political choreography for the ancient world.
Diocletian retired to his massive fortified palace on the Dalmatian coast, in what is now Split, Croatia. When later begged to return to politics amid the empire's power struggles, he reportedly replied that if they could see the cabbages he had grown with his own hands, they would never ask him to trade this contentment for the storms of power again.
Key people: Diocletian, Galerius