The Last Triumph in Rome ~ Diocletian and Maximian's Vicennalia Jubilee of AD 303

Detail of a sculpture from the Arch of Constantine showing the Decennalia or
Five Columns Monument in the background.

Roman triumphs, those vast and glorious celebrations that followed Roman military victories, are beloved of Hollywood directors and epic novelists alike. The vision of the conquering hero riding in a chariot car pulled by a quadriga of white horses with his soldiers marching behind, leading a train of captive enemies through cheering throngs of grateful citizens, scattering coins and good will all around while colossal statues and monuments loom overhead and a humble slave whispers in his ear, “remember thou art mortal” — it is an irresistible scene full of vibrant colors and superlative contrasts. For the record, I thoroughly enjoyed describing one myself at the end of my second book, Belisarius: Glory of the Romans.

But the triumph of Belisarius after his conquest of Vandal Africa happened not in Rome but in Constantinople. This begs the question: when was the last imperial triumph celebrated in the city of Rome itself? The answer seems to be that of Diocletian and Maximian in AD 303 to celebrate their vicennalia as senior Augusti and the decennalia of the Caesars, Galerius and Constantius I. 

Diocletian, who took the throne in AD 284, spent most of his reign at his capital at Nicomedia in the East. It is very likely that he had never visited the Eternal City before arriving there late in AD 303 to begin the celebration of his 20th year as emperor. His plan was to use this event to showcase the achievements of the Tetrarchy he had instituted, including splendid military victories achieved by Galerius over King Narseus of Persia, and Constantius over the usurper Carausius in Britain. 

Details of the triumph of Diocletian are scanty but they do exist both in the ancient sources and in some tantalizing archaeological remains. Writing in On the Deaths of the Persecutors within 10-15 years of the event, Lactantius offers an overview of the triumph from the perspective of a highly educated Christian convert hostile to Diocletian and Maximian:

Click for more info.

The wicked plan having been carried into execution [for the Great Persecution of Christians], Diocletian, whom prosperity had now abandoned, set out instantly for Rome, there to celebrate the commencement of the twentieth year of his reign. That solemnity was performed on the twelfth of the kalends of December [November 20, AD 303]. And suddenly the emperor, unable to bear the Roman freedom of speech, peevishly and impatiently burst away from the city. The kalends of January [December 31] approached at which day the consulship for the ninth time was to be offered to him. Yet, rather than continue thirteen days longer in Rome, he chose that his first appearance as consul should be at Ravenna. [Lactantius, On the Deaths of the Persecutors, Chapter 17]

This passage tells us that Diocletian was most likely in Rome from mid-November through mid-December, so approximately a month. The more sympathetic Eutropius also mentions this triumph hinting that during this time, Diocletian and Maximian may have discussed resigning from office: 

Both of them [Diocletian and Maximian], in the same day, exchanged the robe of empire for an ordinary dress, Diocletian at Nicomedia, Herculius [Maximian] at Milan, soon after a magnificent triumph which they celebrated at Rome over several nations, with a noble succession of pictures, and in which the wives, sisters, and children of Narseus [King of Persia] were led before their chariots.” [Eutropius, Breviarium, Book IX, Chapter 27]

Whether the actual wives and children of the Persian king were displayed, or merely their images is a matter of some debate, with most modern scholars assuming that the family of Narseus had been returned to him long before this time.

Another brief notice of this triumph may be found in the Chronicle of the City of Rome which is part of the Chronography of AD 354, though it is difficult to determine if the items listed here occurred or were dedicated during the triumph itself, or simply during the 22 years that Diocletian was on the throne:

Diocletian and Maximian ruled 21 years, 11 months, 12 days. They gave a largess of 1,550 denarii.  While they were ruling many public works were (re)built: the senate, the forum of Caesar, the basilica Julia, the stage of the theatre of Pompey, 2 porticos, 3 nymphaea, 2 temples, the temple of Isis and Serapis, the new arch, and the baths of Diocletian. They scattered in the circus gold and silver coins. The wall which formed the base of the seating for the boxes in the circus collapsed and crushed 13,000 people; and a woman named Irene gave birth to three boys and a girl. They placed the king of the Persians with all nations and their tunics of pearl in number 32 around the temples of the Lord.  They brought 13 elephants, 6 drivers and 250 horsemen into the city.” (Chronography of AD 354) 

Among the architectural works usually included in the rebuilding of the Roman Forum by Diocletian is the so-called Monument of the Five Columns. This work featured five tall columns set up at the rear of the Rostrum in the Roman Forum to celebrate the decennalia of the Tetrarchy. Each of the columns was topped with a statue—one each of the four Tetrarchs (Diocletian, Maximian, Galerius and Constantius) flanking the middle one featuring a portrayal of Jupiter. We have an idea of what this monument looked like because it is apparently represented in the background of one of the reliefs on the Arch of Constantine. See the photo at the top of this post.

A compact summary of what we know about the Five Columns Monument may be found in this lecture by Prof. Diana Kleiner: The Decennial or Five-Column Monument in the Roman Forum. 

Detail of the surviving base of the Decennial Monument. Click to enlarge.
Image borrowed from here.

Of this monument, only a single column base remains today. Often neglected in the Roman Forum, the base shows a pagan sacrificial procession on two sides, one of the Tetrarchs sacrificing to the gods on the third side, and on the fourth side two winged victories holding a shield inscribed “Caesarum Decennalia Feliciter.” In putting together this blog post, I was struck by the similarity in style and motif between this sculpture and one of the illustrations included with the Chronography of AD 354. See below. 

Illustration from the Chronography of AD 354 (left) compared with the column base
of the Decennalia monument (right). Click to enlarge.

Given that these works were created within fifty years of each other, perhaps the similarities are not surprising. For more on the Tetrarchs Jubliee in Rome, see the chapter: "Memorials of the Ability of Them All": Tetrarchic Displays in the Roman Forum’s Central Area by Gregor Kalas.

Scholars have speculated as to why Diocletian left Rome to accept the consulship for the ninth time in the provincial backwater of Ravenna. Lactantius provides a tantalizing bit of evidence, saying that Diocletian “could not bear the Roman freedom of speech.” What the Romans actually had to say which repelled Diocletian is unclear. We know that Diocletian had imposed eastern customs upon the Roman imperial court, including the usage of ostentatious imperial garb, the expectation that subjects would prostrate themselves in his presence, addressing the Augustus as “Dominus” (Lord), and the proliferation of eunuchs as courtiers. We also know that Roman citizens were not averse to boldly ridiculing an emperor in public. See, for example, the mocking chants which the Romans in the Circus directed at Maxentius in AD 312 while his foe Constantine stood outside the city: “Constantine can not be conquered!” A prolonged encounter between an emperor like Diocletian with a hugely inflated self-image, and a raucous multitude with a tradition of engaging in public mockery of its leaders, could easily have led to ill feelings. 

It is also possible that the garbled account of the Chronography of AD 354 contains a clue. In the passage shown above, mention is made of Diocletian and Maximian scattering gold and silver coins in the Circus. Immediately after is recorded that a retaining wall of the Circus collapsed, killing thousands of people. If such a tragedy happened during the celebration of the jubilee, it certainly would have cast a dreadful pall over the event, and may have been considered a portent of ill omen, (juxtaposed with the more fortuitous news of the birthing of quadruplets). Perhaps the reaction of the Augusti to the disaster was seen by the Romans as unsympathetic or insufficient, and spurred them to speak out loudly against Diocletian, causing the latter’s hasty withdrawal from the city. 

Another possibility is that the ongoing persecution of Christians caused public unrest and antipathy toward Diocletian, who may have discovered upon his arrival that Christianity had a much stronger hold on the Eternal City than he had imagined. According to the account in the Liber Pontificalis, Pope Marcellinus was called to sacrifice to the pagan divinities by Diocletian himself. Lamentably, the Pope conceded and offered incense to the idols. The scandal and outrage caused by such a betrayal must have been furious among the Christian community in Rome, for Marcellinus quickly repented of his perfidy and made a public declaration of his Christian faith. He was condemned to death and beheaded along with four companions. By order of Diocletian, their bodies were left to rot in the streets for 26 days. If this public martyrdom of the Pope in Rome did in fact occur during the triumphal jubilee of the Tetrarchs, one could imagine how it might put a damper on the celebration. Conversely, if this martyrdom had played a role in Diocletian leaving the city early, one might have expected Lactantius to mention it at least in passing.

For a more scholarly but perhaps just as fanciful look into this question, check out Williams, Diocletian and the Roman Recovery, page 188. 

Of course, all of the above is speculation and we can not know for certain why Diocletian left Rome when he did, apparently in a lather, never to return to the Eternal City again. On his trip back to Nicomedia, he toured the Danube frontier and at some point contracted a persistent illness that plagued him all throughout his vicennalial year. By December of AD 304, reports were circulating in Nicomedia that Diocletian had died. 

But the end of Diocletian’s reign and retirement are subjects for a separate post.

Diocletian has featured prominently in numerous other posts on this blog, including:

• Was the Wife of Diocletian a Secret Christian?
• "They Leveled that Lofty Edifice with the Ground" ~ The Destruction of the Church at Nicomedia and Commencement of the Great Persecution
• "Inspired by penitence, he was beheaded." ~ The mysterious last days and death of Pope Saint Marcellinus
• “The Scriptures Destroyed by Fire” ~ An official Roman transcript from the Great Persecution of AD 304
• "The Oblivion of a Silent Age" ~ The effort of Diocletian and Galerius to wipe out Christian literature during the Great Persecution