Key to Umbria

Jovius and Herculius

According to Aurelius Victor, soon after Diocletian had appointed Maximian as his co-Augustus (in 285 AD):

  1. “.... he [Maximian] received the [signum] Herculius from his worship of that deity, just as [Diocletian] received that of Jovius.  This was the also the origin of the names given to those auxiliary units which were particularly outstanding in the army” (De Caesaribus’, 39:14).

These additions to the imperial names indicate that Diocletian and Maximian were (respectively) ‘of Jove’ and ‘of Hercules, implying that each enjoyed the patronage of his associated deity.  With the formation of the first Tetrarchy in 293 AD, each Caesar (Galerius and Constantius) adopted the signum of ‘his’ Augustus.

The significance of these signa is difficult to ascertain.  The most usual explanation is that articulated by C.E.V. Nixon( in Nixon and Rodgers, referenced below, at p 44-5):

  1. “As well as constituting a claim to the powerful support of the Olympians, the names might be intended to symbolise the relationship between Diocletian and Maximian, [with] Diocletian acting as a father figure to his Herculian assistant”.

Joshua Petitt (referenced below) considered other factors that might have led Diocletian to introduce the signa:

  1. He  suggested (at p  48) that Diocletian’s association with Jove, taken together with his military reforms, would have bolstered his position with the legions. 

  2. He also suggested (at p 49) that the adoption of these signa would have made clear the fact that there was no room in the imperial college for the rebel Carausius (below), who had been acclaimed in Britain in 286 or 287 AD.

Stephen Williams (referenced below, at p 69) articulated what was perhaps the most compelling reason for the use of the signa, which was a generalisation of the point about Carausius made above:

  1. “[The most important reason for] this powerful new religious emphasis was the need ... to break with the dangerous tradition that the armies had the right to make Emperors.  If legitimacy ... did not derive from the armies, and not from the Senate, there was only one other source: the gods.”

Joshua Petitt (referenced below), who made a detailed study of the way in which these signa were actually used, concluded from the epigraphic record that:

  1. “the [signa] were not necessarily an official part of the imperial title, but they were recognised as acceptable references to the [corresponding] Emperor”

Thus, the following inscription CIL III 3231 on a votive altar from Sirmium:

I(ovi) O(ptimo) M(aximo) et/ G(enio) h(uius) l(oci)

pro/ salute dd(ominorum) / nn(ostrorum) Iovio(rum)/ et Herculio(rum)

Augg(ustorum) nn(ostrorum)

would have been easily understood as a prayer offered to Jupiter Optimus Maximus and ‘the genius or spirit of this place) for the health of Diocletian and Maximian, identified here only as the Jovian and Herculian Augusti.

Another example of this naming convention was found in Rome, on the inscriptions on two statue bases that were found behind the Theatre of Pompey in Rome.  They had been dedicated by:

Aelius Dionysius, v(ir) c(larissimus), operi faciundo

Aelius [Helvius] Dionysius, of clarissimus rank, supervisor of public works

André Chastagnol (referenced below) suggested that he held this post in 287 AD.  (He  went on to hold a series of important posts, including  proconsul of Africa in 296-300 AD (see below).  The inscriptions under discussion here commemorated (respectively):

  1. Genio Iovii Aug(usti)/ Iovia porticu eius a fundamentis/ absoluta excultaque (CIL VI o255; LSA-1506)

  2. To the Genius of the Jovian Augustus, with the portico of Jupiter having been completed and perfected; and  

  3. Genio Herculei Aug(usti)/ Herculea porticu eius/ a fundamentis absoluta/ excultaque CIL VI o256; LSA-1528)

  4. To the Genius of the Herculian Augustus, with the portico of Hercules having been completed and perfected

These inscriptions recorded:

  1. the completion, presumably by Aelius Helvius Dionysius, of porticoes dedicated (respectively) to Jupiter and Hercules (probably to replace structures that had been destroyed by fire in 284 AD, during the reign of Carinus); and

  2. the erection of statues of the genii (spirits) of the Augusti, each again identified not by name but in terms of his divine patronage. 

The references the genii (spirits) of the Augusti suggests that the bases might have supported cult images. 

Veneration of the Living Augusti


Traditionally, living Emperors were not worshipped as gods in Rome.   Timothy Barnes (1981, referenced below, at page 11) summarised the formal position:

  1. “Panegyrists (orators) might occasionally salute an Emperor as a god on earth, hailing Diocletian as Jupiter and Maximian as Hercules, but officially the Emperors themselves no longer laid claim to divine status.  They were not gods, but the chosen instruments of the gods, their deputies on earth, and in some sense their sons”. 

However, as the statues erected by Aelius Helvius Dionysius in the porticoes of the Theatre of Pompey demonstrate, they were, nevertheless, accorded a particularly exalted status, even within the confines of Rome, in acknowledgement of their extraordinary association with Jupiter and Hercules.

A reference in a panegyric (Panegyric X, translated into English in Nixon and Rodgers, referenced below) offers another window on the Romans’ perception of the Emperors’ ‘almost divine’ status.  The panegyric was delivered at the court of Maximian at Trier in 289 AD to mark the anniversary of the foundation of Rome.  This passage indicates how the Romans experienced the presence of the absent Emperors on that important day:

  1. “O [Maximian], how much more majestic [Rome] would be now, how much better would she celebrate this her birthday, if she were viewing you [in the flesh].  Now, doubtless, her citizens are imagining that you are present by flocking to the temples to your divinities and ... repeatedly invoking Jupiter Stator and Hercules Victor” (13:4).

Commenting on this passage, Elizabeth Marlowe (2010, referenced below) drew particular attention to:

  1. “...  the fact that Jupiter and Hercules are honoured [here] as the [Emperors’] comites ... in the very particular form of their metropolitan Roman cults, Jupiter Stator and Hercules Victor.  [Diocletian and Maximian] are thus praised, but in distinctly local terms, terms that ultimately honour the ancient capital at least as much as they do the Emperors”.

It seems to me that the Romans chose these particular cults specifically because they could be traced back to the earliest days of their city’s history.

It remains to identify these “temples to your divinities”, to which the Romans flocked to experience the virtual presence of the Emperors (or perhaps to pray for their imminent physical relocation to the traditional imperial capital of Rome ?).  The translator of the panegyric, following Nash (referenced below), recorded (at note 48) that:

  1. “The Temple of Jupiter Stator was on the Sacra Via, near the Arch of Titus; that of Hercules Victor in the Forum Boarium.”

However, the situation is more complicated than that.

Jupiter Stator

There were, in fact, two temples dedicated to Jupiter Stator in Rome:

  1. one ‘ad Portam Mugoniam’:

  2. which had been vowed in 295 BC and stood on the site of a ‘fanum’ (shrine) that the Romans believed had been dedicated by Romulus himself (as discussed in the page on Victory Temples and the Third Samnite War); and

  3. which had been rebuilt on the Sacra Via after the fire of 64 AD (as discussed in the page on the Flavian Dynasty: Haterii Temple and the Temple of Jupiter Stator); and

  4. one in the Porticus Metelli (discussed in the page on the Victory Temples of 146 BC)).

The former venerable temple is likely to have been the more important of these for our purposes, particularly on the anniversary of the foundation of Rome.  

It is interesting to note that the base of a statue of Maximian was found in ca. 1530 in this area of the city (in the Farnese gardens, on the northern slope of the Palatine).  The inscription (CIL VI 1125; LSA-820, discussed in the page on the first Tetrarchy) revealed that:

  1. it had been erected by Septimius Valentio, who the vicar of the two Praetorian Prefects in Rome; and

  2. it had been erected after Maximian’s 4th Consulship but before his 5th (i.e. in the period 293-6 AD).

Since the Tetrarchs were usually portrayed together, it is tempting to speculate that this was one of four statues that Septimius Valentio erected to mark the formation of the Tetrarchy in 293 AD.  Whether or not this was the case, Maximian’s statue  was an important commission and we may reasonably assume that its location would have been chosen for its political resonance.  Fortunately, Rodolfo Lanciani (referenced below, search on “PENATIVM”) recorded the find spot (albeit that this was not necessarily the statue’s original location):

  1. “1530: AEDES PENATIVM IN VELIA.  Approximate date of the excavations of Cardinal Alessandro Farnese on the slope of the Palatine, towards the Forum Romanum. 

  2. -Here was found the pedestal ‘Laribus publicis sacrum’ dedicated by Augustus on 1st January [on the 750th anniversary of the foundation of Rome  - i.e. ca. 4 BC],  evidenced by the inscription] (CIL VI 0456). 

  3. -Here must also have been brought to light the large base of marble with a damaged inscription dedicated to Maximian by Septimius Valentio (CIL VI 1125)” (my translation).

This suggests that the statue of Maximian (and perhaps others of his Tetrarchic colleagues) had been erected in the same location as the Temple of the Lares, which can be located by a passage in Augustus’ ‘Res Gestae’;

  1. “I built: ... the Temple of the Lares ‘in summa sacra via’; ...” (4:19).

It was still there in the 3rd century AD, when Solinus included the following information in his account of the locations of the palaces of the original kings of Rome:

  1. “Ancus Marcius [lived] in summa sacra via, where the aedes Larum is situated” (‘De mirabilibus mundi’, 1:23)

I argue in the page on the Flavian Dynasty: Haterii Temple and Temple of Jupiter Stator that this was also the location of the Temple of Jupiter Stator before the fire of 307 AD.

Hercules Victor

There were two temples dedicated to Hercules Victor in Rome, described in the page on the Victory Temples of 146 BC), both in or near the Forum Boarium:

  1. the temple of Hercules Victor in Foro Boario, which was probably next to the Ara Maxima (Herculis Invicti Ara Maxima), which the Romans considered to be the oldest shrine in the city; and

  2. the temple of Hercules Victor ad Portam Trigeminam, between the Forum Boarium and the Tiber.  This was probably the lovely temple that survives today in Piazza Bocca della Verità (illustrated here).

The panegyrist could have had either or both of these temples in mind.  He might have referred (alternatively or additionally) to the Ara Maxima itself: this was not strictly a temple, but it certainly stood in a temenos (sacred enclosure) and a series of dedicatory inscriptions to Hercules Invictus (CIL VI 312-9, ca. 300 AD) found near what was probably its original location, might have related to it rather than to the adjacent Temple of Hercules Victor in Foro Boario. 

Interestingly, the panegyrist’s next paragraph perhaps links Maximian to the Temple of Hercules Victor ad Portam Trigeminam:

  1. “This name [i.e. Hercules Victor] was once given to [Hercules] by the man [identified in other sources as Marcus Octavius Herrenus] who defeated pirates in a merchant vessel and [subsequently] heard from Hercules himself, during his sleep, that he had won the victory with his help.  So it is that, for many centuries, it has been among the duties of your divinity [i.e. of Hercules, the comites of Maximian] to overcome pirates [such as the usurper Carausius, at least according to imperial propaganda].  But surely the day will soon dawn when Rome sees you victorious [with Hercules’ help] ...” (13:5 - 14:1)”. 

Some scholars believe that Marcus Octavius Herrenus built the Hercules Victor ad Portam Trigeminam, and some of those who doubt this nevertheless accept that he might well have dedicated the statue of Hercules Olivarius that stood within its sacred enclosure.

Provincial Cult

The surviving epigraphical evidence, while scant, suggests that the living Tetrarchs were accorded cult status in the African provinces.  Thus, for example, Mustapha Khanoussi and Attilio Mastino, referenced below) published two relevant inscriptions:

  1. An inscription (AE 2003: 2010) records the dedication of a temple at Thibaris  in Africa Proconsularis (modern Thibar, in Tunisia) to the “gens Valeria aeterna”, represented by:

  2. -the Augusti, Diocletian and Maximian; and

  3. -the Caesars, Constantius and Galerius:

  4. ... genti Valeriae aete[r]nae dd(ominorum) nn(ostrorum)

  5. [Imp(eratoris) Caes(aris) C(ai)] Va[ler]i Diocletiani Pii Felicis Invicti Aug(usti) et

  6. Imp(eratoris) Caes(aris) / [M(arci) Aureli Valeri M]aximiani]] Pii Felicis Invicti Aug(usti) et

  7. Flavi Valeri Constanti/ [et]

  8. [Galeri Valeri M]aximiani fortissimorum felicissimorumque Caesarum

  9. templum / [cum omni cultu(?) pleb]s municipii Mariani Thibaritani

  10. devota numini maiestatique ipsorum et

  11. [ordo(?) pecunia statui]s(?) eorum cumulata participantibus secum civibus

  12. suis votiv(a)e devotionis / [a fundamentis(?) in]cohatum perfecit et perfectum

  13. ac dedicatum consecravit [[[ex auctoritate ?]]]

  14. [[[L. Aelii Helvii Dionysii c.v. proconsulis provinciae Africae? et. .. legatorum eius ?]]]

  15. The temple had apparently been started by the municipality before the appointment of Lucius Aelius Helvius Dionysius (above) as proconsul of Africa.  He consecrated and dedicated the temple during his term of office (296-300 AD).  (His name was subsequently erased from this and other inscriptions that recorded his tenure as proconsul).

  16. A slightly later inscription (CIL VIII 14910) from Aïn Tounga (Thignica) in Africa proconsularis (now an archeological site in modern Tunisia) probably (according to Khanoussi and Mastino) commemorated the ‘Geniis diis immortalibus’ (immortal souls ??) of the Tetrarchs:

  17. DDDD(ominorum) nnnn(ostrorum) Impp(eratorum) Caess(arum)

  18. Diocletiani et] Maxim[ia]ni Augg(ustorum) et

  19. Constanti et [[[Maximiani]] nobb(ilissimorum) Caess(arum)] 

  20. [... res pu]blica munic[ipii T]hignicensium dedicante

  21. C(aio) Annio An[ullino proco(n)sule

  22. Anna Leone (referenced below, in Table 2:1, pp 36-7) listed this inscription as evidence of a temple of the imperial cult.  Caius Annius Anullinus was widely documented as Proconsul of Africa in 303-5 AD during the persecution of Christians under Maximian.

It is interesting to note that the imperial cult in Africa was evidenced by two temples in Africa that were probably dedicated to divus Carus during the joint rule of Carinus and Numerian (i.e. in ca. 284 AD), both of which were associated with the Praeses (provincial governor) of Numidia, Marcus Aurelius Decimus (as described in the page on Carus, Carinus and Numerian (282-5 AD)).  Also of note is the fact that the Proconsuls of Africa who built the temples above  during the first Tetrarchy went on to have prominent public careers in Rome itself:

  1. Aelius Helvius Dionysius, the operi faciundo of ca 287 AD and Proconsul of Africa of 296-300 AD, became Urban Prefect in 301-2 AD; and

  2. Annius Anullinus , the Proconsul of Africa of 303-5 AD (or perhaps a member of his family of the same name) became Urban Prefect in 306-7 AD. 

An inscription (CIL III 710) from the province of Illyricum, which was on a marble milestone on the Via Egnatia, read: 

Diis genitis et/ deorum creatoribus

dd(ominis) nn(ostris) Diocletiano et/[Maximiano invic]tis Augg(ustis)

A[---] /AN[---] /I[---] /[---]VIII[---] /[---]VIII / [------

(The repeated numeral VIII probably indicates that the milestone was eight Roman miles form Dyrrachium - later Durazzo, now Durrës in Albania.)   This dubbed Diocletian and Maximian as not only the sons of gods but also progenitors of gods: as Jonathan Bardill (referenced below, at p. 66) observed:

  1. “Clearly, the authors of inscription considered the Augusti to be descended form Jupiter and Hercules and to have created gods by selecting and appointing the Caesars.”

Consecrated Tetrarchs

While living Tetrarchs were not overtly divinised, at least in Rome, such restrictions did not apply after their death.  However, as Frank Trombley (referenced below, at p 22) pointed out:

  1. “The accession of Diocletian in 284 AD ... put an end to the consecratio [of recently-deceased Emperors] ... for two decades.  This was a consequence of the longevity of the Emperors of the [first] Tetrarchy, the first of them to die being Constantius I, ... on 25th July 306 AD [by which time Diocletian and Maximian had abdicated, giving way to the second Tetrarchy].” 

However, a passage in a panegyric (Panegyric VI, translated into English in Nixon and Rodgers, referenced below) that was delivered at Constantine’s court at Trier in 310 AD spelled out how Constantius’ status had changed after his death:

  1. “... immediately, the temples of the Gods were opened for him: he was received by the divine conclave and Jupiter himself extended his right hand to him” (7:3).

Thus, Constantius (like all the Tetrarchs) had been chosen by Jupiter, so his access to the councils of the gods after his death was pre-ordained. 

Sabine MacCormack (referenced below, at p 110) explained how this differed from earlier conventions:

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

Mark Johnson (referenced below, 2009, at p 181) spelled out the procedural change that this implied:

  1. “No longer was the deceased emperor dependent on either the Senate or his successor for obtaining divine status, though these could and [sometimes] did formalise the process.”

This is obviously in evidenced in the case of Constantine’s consecration of Constantius, albeit that none of the other members of the second Tetrarchy followed his (Constantine’s) example (as discussed in the page on Consecrated Tetrarchs (306-11 AD).

Read more:

A. Leone, “The End of the Pagan City: Religion, Economy, and Urbanism in Late Antique North Africa”, (2013) Oxford

J. Bardill, “Constantine, Divine Emperor of the Christian Golden Age”, (2012) Cambridge

J. Petitt, “The Extension of Imperial Authority Under Diocletian and the Tetrarchy, 285-305 CE”, (2012), Thesis (MA) from the University of Central Florida, Orlando

F. Trombley, “The Imperial Cult in Late Roman Religion (ca. 244-395 AD): Observations on the Epigraphy”, in

  1. J. Hahn (Ed.), “Spätantiker Staat und Religiöser Konflikt”, (2011) Berlin

E. Marlowe, “Liberator Urbis Suae: Constantine and the Ghost of Maxentius” in

  1. B. C. Ewald and C. F. Noreňa (eds.) “The Emperor and Rome: Space, Representation and Ritual’ (2010) Yale 

M. Johnson, “The Roman Imperial Mausoleum in Late Antiquity”, (2009) Cambridge

M. Khanoussi and A. Mastino, “Il Culto Imperiale a Thibaris ed a Thugga tra Diocleziano e Costantino”, in

  1. M. G. Angeli Bertinelli and A. Donati (Eds), “Epigrafia di Confine dell’ Epigrafia: Atti del Colloquio AIEGL Borghesi,”, (2003) Faenza, 411–36 

C. E. V. Nixon and B. S. Rodgers, “In Praise of Later Roman Emperors: The Panegyrici Latini”, (1994) Berkeley

S. Williams, “Diocletian and the Roman Recovery”, (1985, second edition 1997) London

T. Barnes, “Constantine and Eusebius”, (1981) Harvard

S. MacCormack, “Art and Ceremony in Late Antiquity”, (1981) Berkeley

A. Chastagnol, “Les Fastes de la Préfecture de Rome au Bas-Empire”, (1962) Paris

E. Nash, “Pictorial Dictionary of Ancient Rome: Volume I”, (1961, 2nd edition 1968) New York

S. Platner and T. Ashby, “A Topographical Dictionary of Ancient Rome”, (1929) London

R. Lanciani, “Storia degli Scavi di Roma e Notizie intorno le Collezioni Romane di Antichità”, (1902) Rome

Diocletian (284-305 AD)

Diocletian's Rise to Power (284-5 AD)      Diocletian and Maximian (285-93 AD)

First Tetrarchy (293-305 AD)      Diocletian, Maximian and Rome (285-305 AD)

Military Campaigns: Maximian and Constantius  in the West (293-305 AD)

Military Campaigns: Diocletian and Galerius in the East  (293-305 AD)

Imperial Cult (285-305 AD)

Diocletian to Constantine (285-337 AD): Literary Sources 

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