Key to Umbria

Last Campaign (305-6 AD)

A  military diploma of 7th January 306 AD (known from the inscription AE 1961 0240) records that Constantius and Galerius had adopted a second title of Britannicus maximus  by that date.  This can only mean that Constantius had sailed from Gaul to campaign in Britain in the previous year, presumably before the onset of winter.  According to the ‘Origo Constantini Imperatoris’ (at 2:4) the victory in question had been secured against the Picts, presumably on or to the north of Hadrian’s Wall.

The nature of this campaign is uncertain.  A strange reference in Panegyric VI (translated into English in Nixon and Rodgers, referenced below), which was delivered to the then Emperor Constantine in 310 AD, four years after Constantius’ death, suggests that this campaign had been criticised at the time on the grounds that Constantius had merely been hunting for spurious victories:

  1. “In the last great campaign of his, [Constantius] did not seek for British trophies, as is generally believed ....” (7:1).

Perhaps Constantius simply felt that he needed to revisit his British subjects as Augustus, and to inspect the work of refortification that had taken place in the ten years since  since his victory against Allectus (described by Bill Leadbetter, referenced below, at pp 158-9) .  However, there is evidence for military action against the Picts, in the form of the Erickstanebrae Fibula (now in the Los Angeles County Museum).  This beautiful gold brooch , which was found in the 1780s in Erickstanebrae (or Ericstane) in Dumfries and Galloway, is inscribed:


This interesting entry in the website reports that:

  1. “Sir Arthur Evans [no less!] agrees that the inscription refers to the vicennalia of Diocletian... [He] suggests that it may have formed part of the insignia sent to Constantius I in Gaul, and that its loss may have been connected with his Caledonian expedition in 306 AD.”

If Sir Arthur was correct (and modern scholars generally agree that the brooch did probably commemorate the vicennalia), then Constantius’ army seems to have penetrated some 50 miles beyond Hadrian’s Wall.

Arrival of Constantine

According to one of the more reliable accounts of Constantine’s famous journey from Galerius’ court to that of Constantius, he caught up with his father as the fleet was about to set sail for Britain:

  1. ... at last, Galerius sent [Constantine] back to his father ....; he caught up with ... Constantius at Bononia [the naval base at Boulogne], which the Gauls formerly called Gesoriacum” (‘Origo Constantini Imperatoris, 2:4”).

This was confirmed in Panegyric VI (above):

  1. “... when your father was crossing the sea to Britain and your sudden arrival [Constantine] illuminated the fleet that was already making to sail, ... you seemed not to have been conveyed by public post but to have flown in some divine chariot” (7:5).

Thus, Constantine must have participated in Constantius’ subsequent campaign against the Picts.

The early accounts of Constantine’s journey all stress its audacity in the face of resistance from Galerius.  However, they disagree as to whether Constantine was responding to the expressed wish of his father, or whether he made the journey on his own volition:

  1. Most sources follow the first line.  For example, according to Lactantius:

  2. Constantius, having become exceedingly ill, wrote to Galerius, and requested that his son Constantine might be sent to see him.  He had made a similar request long before, but in vain; for Galerius [had no desire] to grant it.  On the contrary, he laid repeated snares for [Constantine], although he dared not use open violence, lest he should stir up civil wars against himself and incur that which he most dreaded: the hate and resentment of the army” (‘De Mortibus Persecutorum’, 24:3-4).

  3. In fact, there is no evidence to suggest that  Constantius was ill at this time: indeed he would have hardly set sail for Britain had he really thought himself to be at death’s door.   Nevertheless, it is possible that he requested Constantine’s presence for other reasons. 

  4. Sources who took the second line include Zosimus:

  5. “Constantine, who ... had previously an ambition of being Emperor (but had been more inflamed with that desire since Severus and Maximinus had acquired the name and honour of Caesars), was now resolved to leave [Galerius’ court] and to go to his father Constantius ...  But being apprehensive of seizure on the way, many persons being well acquainted of his anxiety for dominion, he maimed all the horses that were kept for public service ... except those he took for his own use, ... by which means he prevented those that pursued him from going further, while he himself proceeded toward the country where his father was” (‘Historia Nova’, 2:8: 2-3).

Death of Constantius (25th July 306 AD)

According to the ‘Origo Constantini Imperatoris’:

  1. “... Constantius, after winning a victory over the Picts, died at Eboracum [York], and Constantine was unanimously hailed as Caesar by all the troops” (2:4).

Socrates Scholasticus, a historian writing in the 5th century AD, provided the date:

  1. “In Britain,... Constantine was proclaimed Emperor, instead of his father Constantius, who died in the first year of the 271st Olympiad [i.e, in 306 AD], on the 25th of July” (‘Historia Ecclesiastica’ 1.2.1 search on the date in this website of the Wisconsin Lutheran College).

It seems likely that Constantius had intended to spend the winter of 305/6 AD at York after his victory over the Picts, and that he had remained there when he became ill.   With his death, the Second Tetrarchy came to an end.

There is unanimity among the early sources that Constantine was acclaimed by Constantius’ army, as recorded in the ‘Origo Constantini Imperatoris’ (above).  Thus, for example:

  1. “It happened that Constantius died at that time; the guards, therefore, who thought none of his legitimate children to be fit for the imperial dignity, considered that Constantine was a person capable of sustaining it, and conferred the honour upon him in hopes of being remunerated with handsome presents” (Zosimus, ‘Historia Nova’, 2:9).

  2. “... in those very days, in [Britain], ultimate destiny was pressing on ... Constantius.  [When he died] ... as  all who were present, but especially Crocus, King of the Alamanni [who seems to have been the leader of a German cohort that was serving in Constantius’ army],  ... were urging him on, [Constantine] took imperium” (‘Epitome de Caesaribus’, 41: 2-3).

Whether Crocus or the other military leaders knew or cared whether Constantine had been born in wedlock is surely beside the point: he had been fighting with them in the wilds of Caledonia during the previous winter, and we must assume that they been impressed by his performance.  The central question is whether the soldiers acted on their own initiative, or whether they did so after Constantius had commended Constantine to them as his successor. 

A small number of early sources, all of which were biassed in Constantine’s favour, took the latter view:

  1. Two panegyrics (translated by Nixon and Rodgers, referenced below) were explicit:

  2. “... your father [Constantine] had left you imperial power ...” (Panegyric VII, 5:3).

  3. “... manifestly you were chosen, O Emperor [Constantine], by your father’s vote” (Panegyric VI, 7:4).

  4. Lactantius made a similar claim:

  5. Constantius recommended his son to the soldiers, delivered the sovereign authority into his hands, and then died” (‘De Mortibus Persecutorum’, 24:8). Eusebius

  6. Eusebius provided the fullest account of this sort:

  7. Then, taking a final leave of the circle of sons and daughters by whom he was surrounded, in his own palace and on the imperial couch, [Constantius] bequeathed the Empire, according to the law of nature, to his eldest son, and breathed his last” (‘Vita Constantini’, 1:21).

  8. He was surely disingenuous when he implied that Constantius had automatically named Constantine as his heir “according to the law of nature”: Constantius had had other legitimate options:

  9. his designated heir according to normal Tetrarchic conventions was Flavius Valerius Severus; and

  10. the claims of the three sons from his second marriage were arguably superior to those of Constantine on dynastic grounds (since they were also the grandsons of Maximian).  Timothy Barnes (referenced below, 2011, at p 41-2) named them, in what is probably descending order of age, as:

  11. -Flavius Dalmatius;

  12. -Hannibalianus (who seems to have died in childhood); and

  13. -Julius Constantius.

Roberto Andreotti was among the first scholars to publish doubts about the pro-Constantinian version of events: that Constantius had insisted on Constantine’s release from Galerius’ court because he had decided that his oldest son should succeed him.  Andreotti argued that:

  1. “It is unlikely that Constantius wanted to make it easy for Constantine to succeed him, since this would be dangerous for the sons of his second marriage. ... Why then would he call for Constantine in 306 AD?  He had been separated from his illegitimate son for some 17 years.  .... He now had three legitimate sons, the oldest of whom was perhaps 16 years old.  Thus, there was no reason for him to recall Constantine, particularly at that moment” (my translation). 

The implication is that Constantine must have made his dramatic appearance at Boulogne uninvited.  Andreotti point about Constantine’s alleged illegitimacy is probably beside the point: even if he was illegitimate, this had not prevented him from achieving a position of some prominence at the courts of both Diocletian and Galerius.  Nevertheless, other aspects of Andreotti’s argument are entirely reasonable: there is no surviving evidence to suggest that, by this time, he had a close relationship with his father; and it is certainly true that (as mentioned above) his younger half-brothers each had a superior dynastic claim. 

Unfortunately, as he approached death at York in the early summer of 306 AD, the decision for Constantius was not so simple.  Gaul had been a quasi-autonomous unit within the Empire for some two decades, and he had been its de facto ruler for more than half of that time.  He had recovered Britain in 296 AD; and then added Spain to this ‘Empire within an Empire’ in 305 AD.  He now had to make a fundamental decision about its future:

  1. If he died without naming an heir, Galerius (as the new senior Augustus) would let matters take their natural course: the erstwhile Caesar Severus would become the new Augustus; another of Galerius’ nominees would join the Tetrarchy as Caesar; and Gaul, Britain and Spain would be reabsorbed into the Empire proper.  Constantius’ sons would be the natural focal point for any local opposition, so they and perhaps the rest of his family would be at considerable risk from Galerius.

  2. If he named one of his sons as his heir (which, as senior Augustus, he was arguably entitled to do), then Gaul and its associated territories would continue to be ruled by his family.  However, if this heir was to hold on to that power, he would need to command the support of Constantius’ army and the grudging acceptance of Galerius. 

If Constantius had decided on the second option, he might well have judged that Flavius Dalmatius was still too young to be a credible successor.  A better option would have been to commend Constantine to his army, in return for Constantine’s oath that his younger siblings would be protected after his death. 

Birgitta Hoffmann (referenced below, at p 187) seems to have assumed that Constantius had already decided on the second way forward as he was planning his British campaign.  Thus, she suggested that:

  1. “... in a similar manner to other Emperors (especially Septimius Severus), Constantius may have come to Britain [specifically] to provide [Constantine] with the chance of gaining experience at his side, and thus to establish him in the eyes of the army as his heir designate.  If so, then the ploy worked”.

It would be going too far to suggest that this was the only reason for the campaign: Constantine could presumably have established himself in the eyes of the army by fighting on the Rhine frontier.  However, once Constantius had decided to embark upon the British campaign, he might have secured Constantine’s participation in case he himself did not survive it.

One piece of circumstantial evidence in support of this is the fact that Flavius Dalmatius and Julius Constantius apparently did survive, in what seems to have been a comfortable exile (albeit that Hannibalianus probably died in childhood of natural causes).  This is suggested in a poem in which Decimus Magnus Ausonius commemorated his uncle, Aemilius Magnus Arborius, who had been blessed with:

  1. “a wife, noble-born and well-portioned; a home; a professorial chair; the friendship of the great..., while still young, while wealthy Tolosa [Toulouse] held the brothers of Constantine secluded there in nominal exile” (‘Professors of Bordeaux’, 16:2).

The poem goes on to place Aemilius Magnus Arborius in Constantinople, as the tutor to Constantine’s son; this is probably a reference to Constantine junior in ca. 330 AD.  Thus his time in Toulouse had probably dated to the 320s.  We can then assume that Flavius Dalmatius and Julius Constantius were enjoying a relatively tranquil life in Gaul at this time, and that this had probably been the case since the time of their father’s death. 

Unfortunately, there is no evidence that Constantius ever made a public declaration as to his preferred successor: any private declaration would have been of little practical significance.  To all intents and purposes, the decision was taken by his army, with or without his private support.  Constantine might have protected his brothers because he had promised this to his father: however, he might alternatively have done so because he wanted to; and/or because the army would not have tolerated any other course of action.

Read more:

Birgitta Hoffmann, “Roman Invasion of Britain: Archaeology Versus History”, (2013) Barnsley

T. Barnes, “Constantine: Dynasty, Religion and Power in the Later Roman Empire”, (2011) Chichester 

W. Leadbetter, “Galerius and the Will of Diocletian”, London 2009

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

R. Andreotti, “Costanzo Cloro”, Nuovo Didaskaleion (1930) pp 46-7

Galerius I (305-7 AD)     Constantius as Augustus (305-6 AD)

Accession of Constantine (306 AD)   Maxentius and Maximian in Rome (306-7 AD)

Maximian’s Herculean Dynasty (306-7 AD)

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

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