Reconstruction of the Palace of Diocletian, Salona (Split)

As Simon Corcoran (referenced below, 2008, at p 251) observed, when Galerius died in May 311 AD: 

1. “Diocletian, having been near death in 304 AD, was now the only surviving member of the First Tetrarchy”.
   

The Empire was in the hands of the next generation: Maximinus (who replaced Galerius as augustus maximus), Constantine and Licinius.  The rebel Maxentius remained in control of Rome, peninsular Italy and the African provinces, territory that belonged de jure to Licinius.

Diocletian lived in the extensive villa complex that he built at Spalatum, (modern Split, in Croatia), which included his mausoleum (as can be seen in the reconstruction above).  He had lived there since his abdication in 305 AD as a private citizen,  albeit that he had accepted the Consulship of 308 AD and presided over the Conference of Carnuntum in November of that year.  When pressed at that time to return from retirement, he had famously answered:

1. “ ... as though avoiding some kind of plague: ‘If you could see at Salona the cabbages raised by our hands, you would surely never judge [the prospect of a return to power to be] a temptation’” (‘Epitome de Caesaribus’, 39:6).
   

Final Tribulations

Diocletian’s last days seem to have been clouded by his concerns for his daughter Valeria Galeria, the widow of Galerius.  As discussed in the page on Maximinus, Senior Augustus (311-2 AD), she had chosen to move to Maximinus’ territory after Galerius’ death, probably to protect the interests of his son (her son by adoption) Candidianus.  Unfortunately, she fell foul of Maximinus, who banished her from court but refused to allow her to leave his territory. 

According to Lactantius:

1. “... the Empress [Valeria Galeria], an exile in some desert region of Syria, secretly informed her father, Diocletian, of the calamity that had befallen her.  He despatched messengers to [Maximinus], requesting that his daughter might be sent to him.  He could not prevail.  Again and again he entreated; yet she was not sent.  At length he employed a relation of his, a military man high in power and authority, to implore [Maximinus] by the remembrance of past favours.  This messenger, equally unsuccessful in his negotiation as the others, reported to Diocletian that his prayers were vain (‘De Mortibus Persecutorum’, 41).
   

Lactantius then moved on to describe Diocletian’s final humiliation:

1. “At this time [i.e. the time at which Maximian exiled Valeria Galeria (above)], the statues of Maximian Herculius were thrown down by command of Constantine, and his portraits removed; and, as the two old Emperors [Maximian and Diocletian] were generally delineated in one piece, the portraits of both were removed at the same time.  Thus Diocletian lived to see a disgrace which no former Emperor had ever seen, and ... he resolved to die.  ... So he who, for twenty years, was the most prosperous of Emperors, having been cast down into the obscurity of a private station, treated in the most insolent manner and compelled to abhor life, ... expired” (‘De Mortibus Persecutorum’, 42).
   

Death of Diocletian

Unfortunately, there is no unanimity among the early writers as to the year in which Diocletian died.  As Mats Waltré (referenced below, at p 6), for example, pointed out, it could have been in any year between 311 and 317 AD.  The early chronicles tend towards the later part of this period. For example:

1. ✴the Chronicle of St Jerome states that, in 316 AD:
   

2. “Diocletian dies in his villa at Split, not far from Salona, and, alone of all (the Emperors), is declared to be among the gods as a private citizen”; and
   

3. ✴according to Timothy Barnes (referenced below, 1973, at p 33): 
   

4. “... the Consularia Constantinopolitana ... proffers a very precise date for Diocletian's decease: 3rd December 316 AD”. 
   

However, as Simon Corcoran (referenced below, 2008, at p 251) observed:

1. “[While] the year [of Diocletian’s death is uncertain.  ...
   

2. -December 3rd is the day recorded [in the Consularia Constantinopolitana, above]; and
   

3. -Lactantius places his death between those of Galerius and Maximinus, so [if one relies on Lactantius], the year must be 311 or 312 AD”.
   

J. Byron Nakamura (referenced below) believed that, had Diocletian died during the lifetime of Maxentius (i.e. before 28th October, 312 AD), he would have been appeared among the Emperors that Maxentius had commemorated in his dynastic consecration coins (discussed in the page on Maxentius in Rome: (311-2 AD)).  He therefore proposed a later date.  Simon Corcoran (referenced below, 2008, at p 251) also made this point:

1. “Since Diocletian is the only member of the First Tetrarchy not to appear on Maxentius’ divus coinage, and since the latter clearly felt he needed all the help he could get from his recently deceased and deified relatives, Diocletian was presumably still alive in October 312 AD, at the time of Maxentius’ overthrow. This also matches one source which reports that, when Constantine and Licinius issued an invitation to the nuptials of the latter to Constantine’s sister (scheduled for February 313 AD), Diocletian declined it on the grounds of ill-health and this rendered his continued existence obnoxious and suspect to them (‘Epitome de Caesaribus’, 39. 7).  Thus it was probably on 3rd December 312 AD that Diocletian finally expired in his palace at Split ... ”. 
   

However, this presupposes that, like the other Emperors commemorated in Maxentius’ divus coinage, Diocletian had been related to him in some way.  Thus, Timothy Barnes (referenced below, 2010, at p 321) asked rhetorically: 

1. “Could [Maxentius] have minted coins for DIVO DIOCLETIANO PROSOCERO [before his death in October] in 312 AD ?  The answer to this question depends on whether Maxentius’ wife, Valeria Maximilla, was the daughter of Galerius by ... Galeria Valeria, the daughter of Diocletian, or the daughter of [a possible but undocumented] earlier marriage of Galerius to a woman whose name is unknown.  If Galerius married Valeria [Galeria] in 293 AD when he became Caesar ... then [Valeria] Maximilla, who produced a son [Romulus] for Maxentius no later than 307 AD, can hardly be [her] daughter ... Moreover, Lactantius reports that Valeria ... was ‘ob sterilitatem’: prima facie this should mean that she was incapable of childbearing and hence produced no issue by her husband Galerius.”
   

Timothy Barnes conceded that Galerius’ marriage to Valeria Galeria could have pre-dated his accession to the imperial college, and she could have been considered sterile because she had only produced a single daughter.  However, he concluded that:

1. “Diocletian’s absence from Maxentius’ commemorative coinage surely tips the balance of probabilities heavily in favour of the obvious interpretation of Lactantius [i.e. that Valeria Galeria was incapable of childbearing].  ... if Valeria Maximilla was not the granddaughter of Diocletian, then Maxentius was not related to Diocletian in any degree - and the alleged ‘new evidence’ [of Nakamura] is irrelevant to determining the date of his death”.
   

The case is perhaps less clear-cut than this: Valeria Galeria could have adopted Valeria Maximilla (as she adopted Galerius’ illegitimate son, Candidianus).  In that case, Romulus, the son of Maxentius and Valeria Maximilla, whould have been Diocletian’s great grandson by adoption.  An inscription (CIL VI 1138) from what was probably the base of a statue to divus Romulus near the circus in Maxentius’ palace/mausoleum complex on the Via Appia (where Romulus was almost certainly buried), commemorated:

Divo Romulo n(obilissimae) m(emoriae) v(iro)

co(n)s(uli) or[d(inario) I]I

filio / d(omini) n(ostri) Maxent[ii] Invict(i) / [ac perpet(ui)] Aug(usti)

nepoti / [di]vi [M]axim[i]ani Sen(ioris) /

[e]t

divi [Maximiani Iu]/[ni]oris

ac [ .... ]

To divus Romulus, man of most noble memory,

consul ordinary for the second time

son of our lord Maxentius the unconquered and perpetual Augustus

grandson of divus Maximianus senior [Maximian]

and

of divus Maximianus junior [Galerius]

and also ...

It is a great shame that the final fragment was never recovered, since this might well have resolved the conundrum.  As things stand, one can only comment that Maxentius is not known ever to have claimed Diocletian as his wife’s grandfather (or grandfather by adoption), making it unlikely (but not impossible) that she was.

Mats Waltré (referenced below) suggested another way in which one might decide between the dates implied by Lactantius (i.e. 311 and 312 AD): by means of a detailed analysis of the time that must have elapsed between:

1. ✴Maximinus’ exile of Valeria Galeria, shortly after the death of Galerius in May 311 AD; and
   

2. ✴the end of Diocletian’s attempts to negotiate her return, when he was clearly still alive. 
   

He concluded that the elaborate set of interactions described by Lactantius (above) would have taken a considerable amount of time.  Thus:

1. “[While] he death of Diocletian might have taken place at the end of 311 AD, I believe the evidence from Lactantius [on this sequence of events] suggests an earliest date of March, 312 AD.  And, if I were to choose between 3rd December 311 AD and 3rd December 312 AD, I would choose the latter”.
   

I have to say that this probably relies unduly on the detailed accuracy in Lactantius’ account of Diocletian’s negotiations with Maximinus.  His objective was to demonstrate that Diocletian (like other persecutors of Christians) had died in misery, and thus he might well have exaggerated the protracted nature of the process.

Timothy Barnes (as above) preferred to rely on Lactantius’ record that Constantine’s damnation of the memory of Maximian was the final straw that led to Diocletian’s death.  Unfortunately, Lactantius did not specify when this had occurred.  However, Barnes referred back to his own paper of 1973  (referenced below), in which he had observed at (pp 34-5) that:

1. “Lactantius places [Constantine’s damnation of the memory of Maximian] after the death of Galerius ( May 311 AD).  The next step is mere conjecture.  The Consuls recognised in Rome on 3 December 311 AD  were C. Ceionius Rufius Volusianus and Aradius Rufinus.  Perhaps a chronographer has confused this pair ('Volusiano et Rufino') with the Consuls of 316 AD ('Sabino et Rufino'), and thus entered the death of Diocletian under 316 AD when it really occurred on 3rd December 311 AD”. 
   

He pointed out that this would explain the sequence of events described by Lactantius:

1. “[After the death of Diocletian], there still remained one of the adversaries of God [Maximinus], whose overthrow and end I am now to relate ....” (‘De Mortibus Persecutorum’, 43:1);
   

2. “And now [i.e. in late 311 or early 312 AD], a civil war broke out between Constantine and Maxentius ....” (‘De Mortibus Persecutorum’, 44:1);
   

He concluded:

1. “Let it be proposed, therefore, that Diocletian died on 3rd December 311 AD.”
   

It seems to me that Lactantius’ assertion that Diocletian died shortly after Constantine had damned the memory of Maximian should be accepted, even if the causal link  that he proposed is open to doubt.  Of course, we have, once again, the problem that we do not know when this damnation actually occurred.  However, it surely occurred before Constantine’s victory over Maxentius: once Maxentius had been defeated and killed, it would have served no obvious purpose.  

Burial and Consecration

Diocletian was almost certainly buried in the domed crypt of the mausoleum that he had built as an integral part of his retirement villa at Split.  Thus, according to Mark Johnson (referenced below, 2009, at p 59):

1. “[This mausoleum] was probably planned and perhaps begun before [Diocletian’s] abdication in 305 AD, and there is no reason to doubt that it was completed before his death in ca. 312 AD.  Nor can it be reasonably be doubted that [he] was buried here. ... In the 13th century, Thomas Archidiaconus attributed the conversion [of the mausoleum into a church] to John of Ravenna, Bishop of Salona, and stated that, at that time, the ‘idols’ - presumably including the sarcophagus and its contents - were cast out.  The new church was dedicated to the Virgin and St Domnus, and has served as the cathedral of [Split] to the present day”.
   

There are early literary records of Diocletian’s consecration.  For example, according to Eutropius:

1. “Diocletian lived to an old age in a private station, at a villa which is not far from Salona, in honourable retirement, exercising extraordinary philosophy, inasmuch as he alone of all men, since the foundation of the Roman empire, voluntarily returned from so high a dignity to the condition of private life, and to an equality with the other citizens.  [Something] happened to him, therefore, which had happened to no one since men were created: though he died in a private condition, he was enrolled among the gods” (‘Breviarium historiae Romanae’ 9:28).
   

As noted above, the information mirrors that in the Chronicle of St Jerome. However, as Timothy Barnes (referenced below, 1982, at p 35)  pointed out:

1. “Eutropius and Jerome, both probably dependent of the same source, report that Diocletian was consecrated.  That is not only unattested [for example, by consecration coins or inscriptions] but also highly improbable: presumably, therefore, a confusion existed with Maximian [in the original source].” 
   

(The possibility that Constantine consecrated Maximian in ca. 316 AD, having damned his memory in 311 AD, is discussed on what page ??).  

This did not mean that Diocletian was not considered divine after his death: as Sabine MacCormack (referenced below, at p 110) pointed out:

1. “...as a result of Diocletian’s reformulation of the position of the Emperor in life... consecratio underwent a change that endured: the verdict of humans ceased to matter”.
   

In other words, since Diocletian’s reformulation was based on the assertion that he and his colleagues had been chosen by Jupiter, their access after death to the councils of the gods no longer required human intervention.  The two-storey design of Diocletian’s mausoleum seems to have anticipated at least a private cult: Mark Johnson (referenced below, 2009, at p 68) demonstrated that Diocletian’s sarcophagus would have been in the crypt of his mausoleums, while:

1. “... any type of commemorative ceremony would have been performed above the tomb in the upper cella.”
   

The fact that Diocletian was not (apparently) consecrated would not have precluded such ceremonies.

Formal consecration in the Tetrarchic period was first and foremost intended to reflect legitimacy of prospective successors.  The sad fact was that, by the time of his death, his would-be successors were already well-established.  Diocletian had become largely irrelevant in political terms, and no-one (neither Maximinus, nor Constantine, nor Licinius, nor Maxentius) had anything to gain by consecrating him.

Diocletian (died December 311 AD ?)

Burial

Diocletian was almost certainly buried in the domed crypt of the mausoleum that he had built as an integral part of his retirement villa at Split.  Thus, according to Mark Johnson (referenced below, 2009, at p 59):

1. “[This mausoleum] was probably planned and perhaps begun before [Diocletian’s] abdication in 305 AD, and there is no reason to doubt that it was completed before his death in ca. 312 AD.  Nor can it be reasonably be doubted that [he] was buried here. ... In the 13th century, Thomas Archidiaconus attributed the conversion [of the mausoleum into a church] to John of Ravenna, Bishop of Salona, and stated that, at that time, the ‘idols’ - presumably including the sarcophagus and its contents - were cast out.  The new church was dedicated to the Virgin and St Domnus, and has served as the cathedral of [Split] to the present day”.
   

Consecration (?)

There are early literary records of Diocletian’s consecration.  For example, according to Eutropius:

1. “Diocletian lived to an old age in a private station, at a villa which is not far from Salona, in honourable retirement, exercising extraordinary philosophy, inasmuch as he alone of all men, since the foundation of the Roman empire, voluntarily returned from so high a dignity to the condition of private life, and to an equality with the other citizens.  [Something] happened to him, therefore, which had happened to no one since men were created: though he died in a private condition, he was enrolled among the gods” (‘Breviarium historiae Romanae’ 9:28).
   

As noted above, the information mirrors that in the Chronicle of St Jerome. However, as Timothy Barnes (referenced below, 1982, at p 35)  pointed out:

1. “Eutropius and Jerome, both probably dependent of the same source, report that Diocletian was consecrated.  That is not only unattested [for example, by consecration coins or inscriptions] but also highly improbable: presumably, therefore, a confusion existed with Maximian [in the original source].” 
   

(The possibility that Constantine consecrated Maximian in ca. 316 AD, having damned his memory in 311 AD, is discussed on what page ??).  

This apparent absence of formal consecration did not mean that Diocletian was not considered to have divine status after his death: as noted above, Diocletian’s reformulation of the imperial college had been based on the assertion that he and his colleagues had been chosen by Jupiter, so their access after death to the councils of the gods no longer required human intervention.  The two-storey design of Diocletian’s mausoleum seems to have anticipated at least a private cult: Mark Johnson (referenced below, 2009, at p 68) demonstrated that Diocletian’s sarcophagus would have been in the crypt of his mausoleums, while:

1. “... any type of commemorative ceremony would have been performed above the tomb in the upper cella.”
   

The fact that Diocletian was not (apparently) consecrated would not have precluded such ceremonies.

Formal consecration in the Tetrarchic period was first and foremost intended to reflect legitimacy of prospective successors.  The sad fact was that, by the time of his death, Diocletian’s would-be successors were already well-established in their respective territories.  Diocletian had become largely irrelevant in political terms, and no-one (neither Maximinus, nor Constantine, nor Licinius, nor Maxentius) had anything to gain by consecrating him.