Museum Notebook: Diocletian: From Emperor to gardener

View from within the palace of Diocletian in Split, Croatia. Photo / : Kathy Greensides, 2015

It is not every day in Ancient Rome that a Roman Emperor voluntarily abdicates his position, but Emperor Diocletian was the first to do so on 1 May 305 AD. This was his final act in what had been a long and astounding career.

Diocletian, full name Gaius Aurelius Valerius Diocletianus, was born on December 22 in around 244 AD to a family of low status in Dalmatia. He joined the military where he rose to the rank of Cavalry Commander under Emperor Carus. Diocletian was proclaimed Emperor, aged 42, on April 1, 286 AD after the deaths of Carus and his son Numerian during a campaign in Persia.

Diocletian ruled the Roman Empire for 19 years, running many campaigns against the Sarmatians, Carpi, Alamanni, usurpers in Egypt and others. Diocletian was not only a strong military commander, but he also helped institute the largest and most bureaucratic government in the history of the Roman Empire.

He instituted the Tetrarchy (rule of four), standardised imperial taxation, reformed the autocracy and changed the imperial coinage from three coins to five. He was a man who strived to return the Empire to peace and stability following the Crisis of the Third Century.

Antoninianus coin, around 290-295 AD On the head is the bust of Diocletian and on the tail is Diocletian receiving "Victory" from Jupiter. Photo / Whanganui Regional Museum Collection

But all good things must come to an end. Following a bout of severe sickness, Diocletian voluntarily abdicated, on the same hill on which he was proclaimed Emperor.

He retired to his palace in Dalmatia, which in modern times makes up the historic core in Split, Croatia. Here he tended to his gardens, and even when asked to return, proclaimed, "if you could show the cabbage that I planted with my own hands to your Emperor, he definitely wouldn't dare suggest that I replace the peace and happiness of this place with the storms of never-satisfied greed".

Museum Notebook

Remnants of Diocletian's reign can still be found around the world today, from his palace in Croatia, to the many coins minted and dispersed around the Empire.

One such coin, of silver, is in the collection of the Whanganui Regional Museum. It shows Diocletian in all his regalia on one side, and both he and his patron deity, Jupiter, on the other. The reverse side with Jupiter is the most important, as Jupiter can be seen handing "Victory" to Diocletian. This may be referring to Diocletian's earlier victories over Sarmatia and Persia in 285-287 AD. The inscription Concordia militum, or "harmony of the soldiers", emphasises the relationship that Diocletian had with the military and the great reverence that they had for him.

Identifying Roman coins, however, is not always so easy. In relation to this coin specifically, there is uncertainty of the area of Roman Empire it was minted in. Mint marks are often one of the first things to degrade on a coin of this age, making full identification extremely difficult. This coin may have been minted in Heraclea, Siscia or even Antioch. Without the mint mark, we will never know the full story behind it.

• Rachael Mildenhall is the photograph collection researcher at Whanganui Regional Museum.