28 October, 2010

Soemil of Deira

Soemil was an early king of Deira, a territory occupying part of what is now Yorkshire. Historia Brittonum lists him in the Deiran genealogy, with the addition of a cryptic note that he “separated Deira from Bernicia”, implying some important action or event. What do we know about him?

Evidence

Historia Brittonum


61. Woden begat Beldeg, Brond begat Siggar, who begat Sibald, who begat Zegulf,
who begat Soemil, who first separated Deur from Berneich (Deira from Bernicia.)
Soemil begat Sguerthing, who begat Giulglis, who begat Ulfrea, who begat Iffi,
who begat Ulli, Edwin
--Historia Brittonum, available online

Anglian Collection genealogies

Woden Frealafing
Uegdaeg
Siggar
Suebdaeg
Siggot
Saebald
Saefugul
Soemil
Uuesteralcna
Uilgils
Uscfrea
Yffi
Aelle
Eadwine
--Anglian Collection, available online

Anglo-Saxon Chronicle


Ella was the son of Iff, Iff of Usfrey, Usfrey of Wilgis, Wilgis ofWesterfalcon,
Westerfalcon of Seafowl, Seafowl of Sebbald,Sebbald of Sigeat, Sigeat of Swaddy,
Swaddy of Seagirt, Seagar of
Waddy, Waddy of Woden, Woden of Frithowulf
--Anglo-Saxon Chronicle (entry for year AD 560), available online

The lists are broadly similar, with variations in spelling, but not identical. Brond and Baldaeg in the Historia Brittonum list are replaced by Uegdaeg in the Anglian Collection genealogy. Suebdaeg and Siggot in the Anglian Collection list are missing from the Historia Brittonum list. Sguerthing in the Historia Brittonum list is replaced by Uuesteralcna in the Anglian Collection list. From Uilgils/Giulgils onwards, the two genealogies agree (with variations in spelling).

The Anglo-Saxon Chronicle genealogy matches the Anglian Collection genealogy, with variations in spelling, except that Soemil and Saefugul in the Anglian Collection list are replaced by Seafowl in the Anglo-Saxon Chronicle.

Interpretation

Dating

The first king of Deira who can be dated securely is Aelle, father of Eadwine/Edwin. Bede tells us that Aelle was reigning in Deira when St Augustine arrived as a missionary to Kent in 597 (On the Reckoning of Time, Chapter 66 (4557)). Bede also tells us that Aelle was king in Deira when not-yet-Pope Gregory the Great saw some Deiran slave boys for sale in a Roman market and made his famous pun, "not Angles but angels" (Bede, Ecclesiastical History, Book II Ch. 1). This happened before Gregory was appointed Pope in around 590 AD, but after he returned to Rome from Constantinople in around 585 or 586 AD. In an earlier post on ‘Aelle of Deira’, I suggested that Aelle’s reign may have begun around 570 or 575.

Applying the inexact method of counting generations and allowing 25 years per generation, this would place Soemil somewhere around the middle of the fifth century.

‘First separated Deur from Berneich’

The meaning of this intriguing statement is not certain. We can probably be confident that whoever compiled Historia Brittonum, or its source material, thought that this action of Soemil’s was sufficiently important to be worth recording. Moreover, it is the only deed listed for any of the kings between Woden and Edwin, which suggests that it was considered very important indeed.

The kingdoms of Deira and Bernicia were combined, separated and recombined several times during the seventh century, as recorded in Bede’s Ecclesiastical History. The two kingdoms were separate before Aethelferth of Bernicia annexed Deira; I have argued elsewhere that this probably happened in about 605 (see ‘Dating the annexation of Deira’ for the rationale). Aethelferth ruled both kingdoms until his death in battle in 617, after which Eadwine son of Aelle ruled both kingdoms until his death in battle in 633. In 633/634 the two kingdoms were separated, with Deira ruled by Osric (son of Aelle’s brother Aelfric) and Bernicia by Eanferth son of Aethelferth; both were killed within a year. From 634 to 642, both kingdoms were united again under Oswald son of Aethelferth. After Oswald’s death in battle in 642, his brother Oswy ruled Bernicia and Oswine son of Osric ruled in Deira until Oswy had him murdered in 651 (yes, being a king in early medieval Britain was a dangerous job). If the compiler of Historia Brittonum was familiar with this to-and-fro, Soemil’s ‘separation of Deur from Berneich’ may have been seen as Round One in a long-lived dispute.

The founder figure for the dynasty of Bernicia was Ida, whom Bede says began his reign in 547 (Bede, Ecclesiastical History, Book V Ch. 24). At first sight this is a puzzle; if Ida did not found the kingdom of Bernicia until 547, how could Soemil have separated Deira from it a century earlier?

Two possibilities come to mind (besides the prosaic ones that the names or dates are wrong, or that the entry is fictional):

  • Bernicia (or what was to become Bernicia) was in existence before Ida’s reign, and controlled the territory that was to become Deira;

  • Soemil separated Deira (or what was to become Deira) from some political entity other than Bernicia, and the Historia Brittonum chronicler misunderstood or misinterpreted his source.

Although Bede is clear that Ida founded the Bernician (later Northumbrian) royal dynasty, that is not necessarily the same thing as founding the kingdom of Bernicia itself. The name Berneich or Bernicia is of uncertain origin and does not appear to be an Old English name. There seems no reason why the kingdom of Bernicia could not have been in existence, perhaps for some time, before Ida came on the scene. Historia Brittonum provides some support for this in another cryptic remark, saying that Ida united the fortress of Dynguayth with Berneich:

Ida, the son of Eoppa, possessed countries on the left-hand side of
Britain,
i.e. of the Humbrian sea, and reigned twelve years, and united
Dynguayth
Guarth-Berneich

--Historia Brittonum, ch. 61, available online

Dynguayth refers to the site of modern Bamburgh, which the Anglo-Saxon Chronicle says that Ida fortified by surrounding it first with a hedge and then with a wall (Anglo-Saxon Chronicle, entry for 547). The statement that Ida “united” his fortress with Berneich is consistent with Berneich/Bernicia being a kingdom that already existed at the time. If this is the case, there is no indication of when it was founded, and therefore no reason why a kingdom of that name could not also have been in existence in Soemil’s (approximate) period in the mid-fifth century. Such a mid-fifth-century Bernicia would have had to be much larger than the later kingdom of Bernicia, if it controlled the area that later became Deira, but it is quite possible that kingdoms could have varied in size over time as political units consolidated or fragmented.

The second possibility is that Deira in the mid-fifth-century was subject to some other political authority, to which the compiler of Historia Brittonum applied the familiar name Bernicia. Given the date, only a few decades after the Rescript of Honorius telling the inhabitants of Roman Britain to look to their own defences, and the location of Deira, a short distance east of the major Roman fortress of York, a likely candidate for such a political authority would be whatever continued or succeeded the Roman government based at York.

Very little is known about post-Roman York (more about this in a later post). However, if some sort of local or regional government continued in York after the end of official Roman administration, that would be consistent with post-Roman activity observed by archaeology in other Roman cities (see post on Wroxeter) or Roman forts (see post on Birdoswald) in Britain. If Soemil of Deira was subject to a post-Roman ruler based in York and gained independence from his overlord, this might well have been considered worth remembering. By the time Historia Brittonum was compiled in 830 or so, York was under the control of Northumbrian kings of Bernician descent, and in ch. 50 of Historia Brittonum, Ida is described as “the first king in Bernicia, and in Cair Ebrauc (York).”. This is unlikely to be literally true since Bede, who was in a position to know a lot about Northumbrian history, doesn’t refer to Ida in connection with York. It may indicate that the compiler of Historia Brittonum considered that anyone who was a king in York would also be a king of Bernicia (as was the case in the early ninth century when he was writing). In this context, a rebellion against a previous authority based in York could be described as having “first separated Deira from Berneich”. Indeed, since there are no contemporary records of fifth-century names, any such post-Roman political entity based in York might even have been called Berneich for all we know (although something based on the Roman name Eboracum or its Brittonic equivalent Caer Ebrauc might seem more likely). If it was a polity covering most or all of the territory controlled by the Roman Dux Britanniarum, it would have extended from York to Hadrian’s Wall and could have taken a name equally easily from anywhere in the region.

The most famous account of a rebellion by an English leader against a post-Roman British overlord at some time around the middle of the fifth century is of course the tale of Hengest’s revolt against his employer Vortigern. Variations of the story are told in Bede, Gildas, the Anglo-Saxon Chronicle and Historia Brittonum. Briefly, Vortigern was a ruler of part or all of Britain after the end of Roman administration, and hired Germanic mercenaries led by Hengest to protect Britain from the Picts in exchange for grants of land and regular pay. Hengest’s troops defeated the Picts, demanded more cash and more land (obtaining Kent, Essex and Sussex by treaty from Vortigern), sent for friends and relatives to join them in Britain, then rebelled, murdered many of the British leaders (but not Vortigern), and plundered large areas of Britain in a destructive raid. Bede dates these events to the middle of the fifth century (Book I, Ch. 15; he gives the initial arrival of Hengest as AD 449, but the sequence clearly took place over an extended period).

The coincidence in approximate dates raises the intriguing possibility that Soemil in Deira might also have been a captain of English federate troops, who was hired under similar terms to Hengest and who rebelled at the same time. This is the sort of thing that might well have been remembered in oral tradition, perhaps hazily as time went on, to be written down centuries later as a cryptic note in Historia Brittonum. I need hardly say that this interpretation is speculative.

Speculating further, it may be noteworthy that the genealogies disagree about Soemil’s immediate successor. The Anglian Collection and Anglo-Saxon Chronicle give the name of Soemil’s successor as Uuesteralcna or Westerfalcon, Historia Brittonum says it was Sguerthing. Furthermore, in all the genealogies there is a change from the succession of S- names up to and including Soemil to a succession of names beginning with a vowel (W = uu). This change happens immediately after Soemil in two of the genealogies, and after his successor in the other, and is consistent with (but does not prove) a change of dynasty, from a family that favoured names beginning with S- to a different family that favoured names beginning with a vowel. Possibly there were different family factions among the Deiran aristocracy in the mid-fifth century, and possibly Soemil’s ‘separation of Deira from Berneich’ ended up having adverse consequences for his faction or family. If the ‘separation’ turned out to be temporary, perhaps Soemil’s faction was displaced by a rival group when it was reversed. Or if the ‘separation’ involved breaking the terms of a treaty or agreement, perhaps a rival faction disagreed and took the opposing side.

From the single line in Historia Brittonum and the genealogies, we can reasonably infer that Soemil lived some time around the middle of the fifth century, and that he was remembered for gaining independence for Deira from some other political entity. What that entity was, whether Soemil’s independence from it was temporary or permanent, how it was achieved, what its consequences were, and whether it had any connection with the more famous and roughly contemporary rebellion of Hengest against Vortigern, are open to question.

References

Anglian Collection, available online
Anglo-Saxon Chronicle, available online
Bede. Ecclesiastical History of the English People. Translated by Leo Sherley-Price, Penguin Classics, 1968, ISBN 0-14-044565-X
Bede, The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press, 1999, ISBN 0-85323-693-3.
Historia Brittonum, available online

Map links

Bamburgh
York

12 comments:

Rick said...

Tangential to the main point, but do we even know the original, native forms of these names? 'Bernicia' sounds like it ought to be in Italy, presumably because it is Latinized; compare 'Berneich.' But that may not be the original form either.


A 'post-Roman political authority' might not originally have any territorial name, any more than the Roman Empire itself did. Dux Bellorum has a distinctly period flavor, and implicitly claims some form of authority over all of Britain, or at least ex-Roman Britain.

If this entity later comes to be called something like Bernicia, reality must be setting in, that the effective authority is only regional. Which might have been the case in practice from the outset, given the probable evaporation of any Roman tax collection system.

As I recall, the basic late Roman system was that the local officials of civitates were responsible for taxes, so they were probably happy enough to see the end of Roman central administration, and not one bit eager to replace it with new tax collectors.

Carla said...

Rick - No, not for sure. Bernicia is Latinised and occurs in Bede, so was in use by 731. Historia Brittonum was written in 830-ish (according to its prologue) but Berneich may be derived from older source material. How far back it really goes and who used it is not known.

Roman Britannia did have regional names; it was divided into four provinces called Britannia Prima, Britannia Secunda, Maxima Caesariensis and Flavia Caesariensis, plus a fifth province called Valentia. Plus it had the tribal names of the civitates at a more local level. Not that these are much help in tracing the origin of the early medieval regional names, with a few possible exceptions like Votadini/Gododdin and Demetae/Dyfed, but they do indicate that regional authority was not an entirely new concept.

Dux Bellorum looks to me like a job title. How does it implicitly claim authority over all Britain, or all ex-Roman Britain?

Indeed, (some of) the local civitates may not have been much distressed to find that they no longer had to pay taxes to provincial, diocesal or imperial levels of authority, especially if the services provided by higher authority were no longer effective. As with so many other things, there may have been differences of opinion; the Appeal to Aetius may indicate that some would have preferred to have the Empire back.

Rick said...

Dux Bellorum is indeed a job title. And you are right that nothing in the title itself implies a scope. But this is no ordinary job title, it is Arthur's job title when he first shows up in the historical record in the HB. Whatever is said of Arthur, the title sounds authentic.

And it fits a pattern of pan-British commanders in chief who are specifically NOT described, at any rate by Gildas, as kings or emperors. Vortigern is 'supreme tyrant' or usurper (of what, exactly?). I'm not sure Gildas gives any title or job description to Ambrosius Aurelianus, but clearly understands him as some sort of generalissimo, with pan-British scope.


There were probably differences of attitude toward Roman authority, and certainly times changed. My impression is that the earlier 400s were relatively peaceful, and the local elite probably didn't miss paying for protectors who would end up claiming the purple and sailing off across the Channel with their troops, never to be seen again.

By the time the Appeal to Aetius is sent, all hell is breaking loose. Unfortunately for whoever wrote it, all hell is breaking loose everywhere.

But googling around on the Appeal, I just noticed something interesting. The 'barbarian' problem is all with Scots and Picts. The Saxons aren't a problem until Vortigern hires them as auxiliaries, and they turn on him.

Maybe Hengist decided that he didn't want to be the English Stilicho, considering what happened to the real Stilicho, and being the English Theodoric was a better bet - but he didn't quite bring it off.

But Saxons certainly didn't just show up out of nowhere in 447 - it is the Saxon 'problem' that seems to arise suddenly, after political developments get out of hand.

Carla said...

Yes, it is an interesting and sometimes overlooked point that in Gildas' story the Scots and the Picts were the primary enemy. It's also worth noting that Gildas says that after the Appeal to Aetius "then, too, the Picts for the first time seated themselves at the extremity of the island". Ammianus Marcellinus refers to Picts in the Barbarian Conspiracy of 364, and the name appears as attackers of Roman Britain as far back as about 297, so it seems extremely unlikely that the Picts really were new arrivals in the 440s. Whether Gildas meant this as rhetoric for dramatic effect, or whether he meant they had now suddenly become a problem for the first time (although Hadrian and Antoninus might have begged to differ), or whether he was just mistaken, is anyone's guess.
HB also says that in Vortigern's time the Britons were afraid of the Romans and Ambrosius, as well as the Picts and Scots. There seems to have been rather a long list of potential enemies, and the Saxons don't seem to have been at the top of it.

Assuming that there really was a Hengest working as a mercenary leader in Britain in the 440s, Stilicho's career might well have looked like something of a cautionary tale - put not your trust in emperors. Hengest may have considered that he was getting his retaliation in first. Hengest got Kent ceded to him by treaty, so at a local level he may have been a sort of Theodoric on a smaller scale. If Roman Britannia fragmented quickly after 410, small scale might have been all that was available in practice by the 440s.

Gabriele C. said...

I don't think Stilicho was the role model, more likely the more 'heroic' German leaders like Alaric, Geiseric, Ricimer ... There were some success stories of German warlords / kings that may have found their way to Britian, probably in an already 'enhanced' version. ;)

Rick said...

I think the Picts and Scots are mostly ignored, because they do not fit the popular tropes, either Romans v (Germanic) barbarians or Celts v Saxons.

Saxons presumably had been an issue in the past; we've discussed what 'Saxon Shore' meant, but apparently they hadn't been a problem in the decades before c. 440. And since the Picts surely were in Britain before that time, Saxons could easily have been as well.

It occurs to me that Saxons could be been both peacefully well established and still 'foreigners.' If Lundenwic turns out to have been founded pre-440, its location could be indicative that it was a sort of trade settlement or steelyard.

Hengist's name does not inspire much confidence in his historicity, though it might have been a nickname. The story itself is generally plausible.

Regarding fragmentation, that does raise a puzzle about how the Roman administration in Britain simply evaporated. Perhaps there was not much to evaporate. I tend to picture a regional administration that would keep going unless forcefully dislodged, but I suppose the actual official Roman presence was much 'thinner' than that, except for the army which was already gone.

Carla said...

Gabriele - There must have been a lot of story and saga in circulation that hasn't come down to us. Plus opportunistic reaction to immediate circumstances doesn't always need a role model.

Rick - there's a reference to Saxons as part of the Barbarian Conspiracy in 364, though I think Ammianus refers to them in the context of attacking Gaul alongside the Franks. Indeed, it is perfectly possible for a people to be peacefully settled and still 'foreigners'. One of the meanings of the Old English 'wic' is a trading settlement, and Bede knew London as a cosmopolitan trading centre with merchants from many countries in 685. It was fairly cosmopolitan in the Roman period too, and may have retained some of that character in between.
It's been suggested that Hengest could have been a nickname. I think I have seen a theory that it could have been some sort of title, perhaps related to horsehair plumes on helmets, but don't quote me on that. The eponymous founder of the East Anglian Wuffing royal dynasty was called Wuffa, meaning 'wolf', so maybe animal names/nicknames were common practice.

Honorius wrote to the civitates in 410, which may indicate that any regional (the 4 or 5 provinces) or diocesal government had already gone by then, or it may indicate that a higher level existed and Honorius was refusing to acknowledge it. The story about Vortigern ceding Kent to Hengest over the head of its local king implies that Vortigern had, or claimed to have, some sort of authority above the civitas level, but doesn't of itself tell us how wide such authority was or how widely recognised/accepted. As we've discussed here before, the situation may have been fluid, with local regions combining and fragmenting and recombining in various combinations according to fluctuating military and political circumstances. Perhaps a little like the way the assorted regions of medieval Wales tended to get consolidated under powerful individual leaders, like Owain Gwynedd or Llewellyn Fawr, and then promptly fragment again on their deaths. Some theories suggest that Roman provincial and diocesan administration was always pretty thin, not much more than a veneer floating on top of the civitates as the main political units.

Would-be Emperors tended to take the mobile field army with them in their bid for the top job. Static frontier garrisons like the units on Hadrian's Wall may have stayed on, although they stopped being paid by the central imperial administration in Rome so the Army wages had gone even if the garrison army hadn't. This is consistent with the post-Roman developments seen at forts like Birdoswald; somebody was still living there, and in some style, though not in the type of buildings we normally associate with Rome.

Carla said...

Gabriele - There must have been a lot of story and saga in circulation that hasn't come down to us. Plus opportunistic reaction to immediate circumstances doesn't always need a role model.

Rick - there's a reference to Saxons as part of the Barbarian Conspiracy in 364, though I think Ammianus refers to them in the context of attacking Gaul alongside the Franks. Indeed, it is perfectly possible for a people to be peacefully settled and still 'foreigners'. One of the meanings of the Old English 'wic' is a trading settlement, and Bede knew London as a cosmopolitan trading centre with merchants from many countries in 685. It was fairly cosmopolitan in the Roman period too, and may have retained some of that character in between.
It's been suggested that Hengest could have been a nickname. I think I have seen a theory that it could have been some sort of title, perhaps related to horsehair plumes on helmets, but don't quote me on that. The eponymous founder of the East Anglian Wuffing royal dynasty was called Wuffa, meaning 'wolf', so maybe animal names/nicknames were common practice.

Honorius wrote to the civitates in 410, which may indicate that any regional (the 4 or 5 provinces) or diocesal government had already gone by then, or it may indicate that a higher level existed and Honorius was refusing to acknowledge it. The story about Vortigern ceding Kent to Hengest over the head of its local king implies that Vortigern had, or claimed to have, some sort of authority above the civitas level, but doesn't of itself tell us how wide such authority was or how widely recognised/accepted. As we've discussed here before, the situation may have been fluid, with local regions combining and fragmenting and recombining in various combinations according to fluctuating military and political circumstances. Perhaps a little like the way the assorted regions of medieval Wales tended to get consolidated under powerful individual leaders, like Owain Gwynedd or Llewellyn Fawr, and then promptly fragment again on their deaths. Some theories suggest that Roman provincial and diocesan administration was always pretty thin, not much more than a veneer floating on top of the civitates as the main political units.

Would-be Emperors tended to take the mobile field army with them in their bid for the top job. Static frontier garrisons like the units on Hadrian's Wall may have stayed on, although they stopped being paid by the central imperial administration in Rome so the Army wages had gone even if the garrison army hadn't. This is consistent with the post-Roman developments seen at forts like Birdoswald; somebody was still living there, and in some style, though not in the type of buildings we normally associate with Rome.

Rick said...

Stilicho would certainly seem like a negative example, but to an auxiliary officer who happened to be Saxon, rising in 'Roman' command would seem the natural course.

Honorius (or his chancery) might naturally write to the civitates, if he was responding to some sort of provincial delegation. On the other hand this was no ordinary request.

It is hard to feel sorry for Honorius, but the poor guy was in a box. Even if there were still a functioning Roman government, telling the provincials to follow the directives of the Dux Britanniarum would pretty much be an invitation for that gentleman to assume the purple. Better emperors than Honorius would resist doing that.

All of this said, for practical purposes the 'Fall of the Roman Empire' in Britain happened when the pay stopped.

Unpaid troops usually melt away, or else do a Spanish Fury on the local population and then melt away. I imagine the auxiliaries that remained were more like military colonists than regular soldiers. They would naturally stay on, and would tend to obey their local commanders. But even if they still acknowledged the chain of command, it would tend to be 'I obey, but I do not comply.'

It is quite plausible that various individual leaders - Vortigern, Ambrosius, and Arthur, perhaps, and maybe others - made some credible assertion of wider authority that lasted as long as they were alive and successful.

Carla said...

Pay and supplies may well have been erratic even before the official end of Roman administration, given all the upheavals in the late fourth and early fifth century, so even that may have faded out rather than abruptly stopping overnight. It may have been a case of the intervals between arrival of pay, supplies and orders getting longer and longer, until it eventually became apparent that there wasn't going to be a next shipment or a next order, or circumstances demanded action without one. If so, local commanders who had adapted to erratic pay by collecting taxes in kind and using it themselves may simply have carried on. This might have varied in different localities as well, according to circumstance and the attitudes of commanders and garrisons. How they, or their successors, would have reacted to a Vortigern or Arthur or Ambrosius coming along in the 440s and announcing that he was now the Imperator/Governor/Dux Britanniarum and they should obey him, is anyone's guess and might also have been variable. In later times the ability of a leader to maintain control over a wide area - what Bede calls 'imperium', or what we can see at times in medieval Wales - depended on the personal prestige and ability of the leader himself. It seems very likely that if Arthur/Ambrosius/Vortigern/anyone else did manage to obtain wider authority, it is likely that it was personal, had to be earned and maintained, may have contained the seeds of its own destruction if you had to defeat rivals before they could be forced to become your allies/subordinates (which would naturally cause resentment and/or desire for revenge), and wasn't a stable institution that could easily be handed on. Which would be consistent with HB's mention of conflict between Ambroisus and Vortigern, and the internal conflicts in the Arthurian legends.

tallhwch said...

I have read through John T. Koch's 'Y Gododdin' translation (1997) and even a linguist isn't able to suggest a much more primitive form than Berneich. In the Roman Empire, the title 'Dux Brittanorum' was assigned to a northern regional commander, probably if not fully using Hadrian's Wall. The legend of Hengest and Vortigern is a messy one to untangle but we do know from Insular, Roman, and other continental sources that the Germanic people were in Britain well before 410 and participated in the events that created post-Roman Britain.

I have a query for you. For the above reasons and through various other means Soemil has often been connected to the mid-fifth century. Do you think he might have been a key or the only participant in the 441x446 rebellion Gildas speaks of as occurring just before the request to Aetius?

Carla said...

Tallhwch - hello and welcome! Dating Soemil is very approximate. As far as I know he appears in no other sources, so the only clue is in counting generations back from the first dated figure, Aelle of Deira. I used 25 years/generation, which for 5 generations gives 125 years, which puts Soemil around the mid fifth century relative to Aelle in the late sixth. Using 30 years, though, would put Soemil in the early fifth century. So he could have been contemporary with the rebellion (or whatever it was) that happened just before the appeal to Aetius, but I don't think it's possible to date him definitively to that specific time period. He might have been around then, or he might have been earlier or later. If he was around then, he might or might not have been involved in events. Soemil seems to have been active in what is now north-east England, since he is in the Deiran king-list and is remembered for something he did in relation to Bernicia. Assuming those names were being used to indicate roughly the same geographical areas as Bede uses them for, that puts him in the area of York to Hadrian's Wall, approximately. Is there anything to associate either Soemil himself or this area specifically with the appeal to Aetius?