Offa and the Mercian Wars

by Chris Peers

  Aethelberht the Martyr

  East Anglia, still ruled by the descendants of Raedwald, seems to have accepted Mercian overlordship peacefully since the time of Aethelbald, but towards the end of Offa’s reign an incident occurred which has affected his reputation ever since. In 794 the young king of the East Angles, Aethelberht, travelled to Mercia to ask for permission to marry Offa’s daughter. The bare bones of the story appear in the Anglo-Saxon Chronicle, which states that ‘Here Offa ordered King Aethelberht’s head to be struck off.’ Several later medieval lives of Saint Aethelberht, as he was to become, provide further details. The most elaborate of these was written by Osbert of Clare, who as prior of Westminster Abbey in late twelfth century had custody of Aethelberht’s head, preserved there as a holy relic. Osbert was also an East Anglian, and so had an additional reason to portray the saint in a favourable light.

  According to his account the young king was born in 779, so was no more than 15 years old at the time of his death. When he was 14 he had succeeded his father on the throne and had been urged to marry, but being a very serious and religious youth he had found it difficult to choose a suitable queen. Eventually his advisers suggested Offa’s daughter Alfthrytha, and despite the objections of his mother, who distrusted the Mercians, the king decided to visit Offa and ask for her hand. Ignoring various ominous signs and portents along the way, he continued his journey and eventually arrived at Sutton near Hereford, where Offa’s court was staying. According to Osbert, Alfthrytha saw him approaching at the head of his retinue and was impressed by his splendid appearance, but the girl’s mother, Queen Cynefrith, apparently alarmed by her daughter’s enthusiasm for the match, persuaded Offa that his guest was planning an invasion of Mercia. The king therefore ordered him to be seized and executed, entrusting the deed to a certain Winbertus, a wanted murderer who had taken refuge at court. Winbertus then asked Aethelberht to disarm before entering Offa’s presence, shut him inside the hall and beheaded the boy with his own sword. The body was thrown into the River Lugg, but was later recovered after the usual miracles revealed its location. Offa was stricken with remorse and endowed various churches and monasteries by way of penance.

  The story has become well known, but can hardly be accepted at face value. Even if we concede that Osbert or the source on which he drew preserved a genuine memory of events, their obvious East Anglian bias must be taken into account. The role of Cynefrith cannot be confirmed, and may be a device to avoid putting the blame for the crime onto a respected monarch such as Offa. Her husband had married two other daughters to the kings of Northumbria and Wessex, and can hardly have objected to another dynastic match as such, especially as Aethelberht is unlikely to have ridden across Mercia without some kind of invitation, or at least acknowledgement that his suit would be welcome. Offa may of course have deliberately lured him into a trap, but his motive is unclear. It has been pointed out that Aethelberht had begun to strike coins which, unlike previous East Anglian issues, omitted Offa’s name, and that this might have been, or been mistaken for, a bid for independence. Osbert remarks in passing that an earthquake as the young king set out terrified ‘the whole war band’, which reminds us that no Anglo-Saxon king would have travelled without a substantial bodyguard. Perhaps his following was large and well equipped enough to be mistaken for an invading army, or at least to outnumber the troops at the Mercian court and give rise to genuine alarm. Whatever the circumstances, Offa seems to have profited by the incident despite his alleged remorse, as Matthew of Westminster says that he immediately dispatched an army which brought the leaderless East Angles under his direct control.

  Offa’s Dyke

  The achievement for which Offa is best known today is of course the building of the dyke bearing his name along the Welsh border. A great deal of attention has been given to the questions of how, why and exactly when Offa built this great earthwork – but much less to whether he actually built it at all. The evidence is surprisingly thin. The first documentary evidence comes from Asser’s Life of King Alfred. Asser was writing in the 890s, more than a century after the generally accepted date for the construction of the dyke, and he mentions it only in passing. ‘In fairly recent times’, we are told, a ‘vigorous king’ of Mercia called Offa ‘had a great dyke built between Wales and Mercia from sea to sea.’ Several other medieval writers mention the dyke and associate it with Offa, including Simeon of Durham, Gerald of Wales and Walter Map. The first account written in Welsh appears to be the ‘Brut y Saeson’, which dates from the fifteenth century and describes the dyke as Offa’s response to a series of Welsh raids in 783 and 784. However, these accounts are all much later than Asser and cannot be regarded as independent sources. Certainly various parts of the feature have long been known locally by names associating it with Offa, but this cannot be considered as proof unless we are also prepared to accept Wansdyke on the Wiltshire Downs, or Grim’s Dyke east of Cambridge, as evidence for the personal involvement of Woden and the Devil.

  It will be objected that Offa was a known historical figure, but his very eminence would tend to attract associations with anything mysterious in or on the frontiers of his kingdom. This process is evident even today: in 2009 and 2011, for example, the local press in Tamworth found Offa a useful asset in raising the profile of their campaign to keep the Staffordshire Hoard in the town. The hoard almost certainly predates his reign by at least 100 years, but Offa, as the only Mercian king most readers will have heard of, was an obvious headline-grabber. What is more, in the eighth and ninth centuries the phrase ‘Offa’s Dyke’ would have had connotations entirely lost to later generations. The genealogies in the Anglo-Saxon Chronicle trace the descent of both Offa and Penda from Offa, son of Waermund, who was believed to have ruled in the Angles’ Continental homeland twelve generations before his Mercian namesake. This ‘Offa of Angeln’ was a famous hero of Germanic legend, mentioned in Beowulf and in ‘Widsith’, which from its archaic language is thought to be the earliest surviving English poem (Stenton). According to the latter source, Offa, while still a young man, ‘won by warfare the greatest of kingdoms’, generally identified with the base of the Jutland Peninsula and the region of the River Eider in North Germany. Here, the poem continues, ‘he set out the boundary against the Myrgings, by Fifeldor, and ever thereafter they held it, the Angles and the Swabians, as Offa struck it.’ In other words his most lasting achievement was to establish a fixed boundary against a previously hostile neighbour; this most likely involved the building of some sort of fortified line ‘from sea to sea’, which was certainly how later generations interpreted the story.

  If we are prepared to accept the idea that Offa of Mercia did not necessarily plan and build the immense work which bears his name from scratch, this removes many of the difficulties with its dating. It has always been difficult to identify any point in his reign, or in those of his predecessors and successors, when the military situation would have justified such an undertaking. As we have seen, a late Welsh source states that it was built in response to Welsh raids in the 780s, but the more closely contemporary Welsh Annals records only English invasions of Wales during this period. If the dyke was really built at this time, the Mercian armies were pushing beyond it almost as soon as it was completed. Furthermore, recent archaeological work has led to little agreement on the nature and function of the dyke, which is understandable if different sections were built by different groups for their own various purposes. Less than a fifth of the course of the dyke runs along current parish boundaries, which has been used as evidence that it was in fact driven through by a single ruthless leader, dividing communities where military strategy dictated, regardless of local sensitivities (Fox). However, this argument only holds if the parishes were already in existence in the eighth century, which has not been proven. If they were not established until later, it may only indicate that the dyke was not considered a major obstacle.

  Similarly, it has been pointed out that according to place name evidence, severa
l long-established English-speaking settlements with names such as Thornbury, Woodiston and Downton were marooned on the western side. This is especially noticeable where the dyke runs east of the River Severn south of Welshpool, and south of the River Lugg between Knighton and Kington. This could be an indication of Offa’s ruthlessness, abandoning fellow Englishmen to the enemy as part of a political compromise, or simply in order to keep the frontier on the most easily defensible line. Clearly the Welsh did not immediately descend from the hills and wipe them out, or their villages would not still retain their English names. On the other hand, it is hard to see why Offa would have needed to sacrifice any Mercian territory in view of his military predominance during this period.

  One recent interpretation suggests that the central portion of the dyke, marking the border with the kingdom of Powys, was indeed a single construction undertaken by Offa in the 770s and 780s, but that other unrelated works gradually became associated with it, leading to Asser’s mistaken belief that it extended ‘from sea to sea’ (Hill and Worthington). This theory accounts for many of the gaps and anomalies in the construction, but may still be stretching the evidence a bit too far. It relies first of all on the idea that a resurgent kingdom of Powys could have presented a threat to Mercia. The evidence for this comes from an inscription which was once legible on the Pillar of Eliseg, a monument to the king of that name which still stands a few miles north of Llangollen. As recorded in 1696 by Edward Lluyd, this stated that it had been erected by Eliseg’s great-grandson Cyngen ap Cadell in honour of his ancestor, who had ‘annexed the heritage of Powys throughout nine [years] from the power of the Saxons.’ The end of Cyngen’s reign can be dated to around 855, so it is quite likely that Eliseg was a contemporary of Offa, but there is no other evidence for his career, and his conquest (or reconquest) of Powys must have been only temporary. It is hard to believe that the ‘vigorous’ king Asser describes would have responded to the loss of a client kingdom by walling it off with a great defensive line, then immediately rendered it obsolete by sending his armies westwards again.

  There is also the objection that even this section of the dyke cannot have been much use as a military obstacle. No trace has been found of a wooden palisade along the top of the bank, nor – despite a few unsubstantiated claims – of forts or watchtowers associated with the work. It is not even certain that the ditch was always on the western side, even in the central sector. Where there are the remains of a ditch on the eastern face, these are usually interpreted as incidental products of the construction process, perhaps where earth or turf was excavated to raise the height of the bank. However, there are stretches where the eastern ditch seems to have been deeper and better demarcated than the western one, which is hard to explain if it was built to keep out invaders coming from the west (Bapty). It has often been noted that for most of its course the dyke is carefully sited to overlook the terrain to the west, but this would be of very limited value unless it was continuously manned throughout its length.

  With the current state of knowledge the easiest way to resolve most of these difficulties is to accept that most of the dyke as we know it is not a single coherent defensive line, but was created by linking up already existing earthworks of different origins. That these broadly followed the line of the Mercian – Welsh border is not surprising, as this corresponded to a geographical frontier between the English lowlands and the Welsh hills which had probably dictated political boundaries since pre-Roman times. It is also possible that some features never were linked to the main dyke, but have been associated with it by modern investigators who have taken Asser’s ‘sea to sea’ remark too literally. At some point before Asser wrote, a powerful Anglo-Saxon ruler must have undertaken the formidable task of joining the works on the frontier with Powys into a single continuous line, but probably not with a narrowly military function in mind. The dyke looks more like a prestige project intended to overawe the peoples beyond, sited, perhaps, to be seen from afar rather than to provide a (non-existent) garrison with lines of sight to the west.

  There is also reason to believe that the instigator of this project was not Offa himself but one of his predecessors. As we have seen, Offa went to great lengths to safeguard his rights to demand fortification work from his subjects, but although this explains how he could have mobilised the necessary manpower, similar obligations had existed before his reign. As discussed in Chapter 3, Aethelbald introduced compulsory fortification work and was even criticised by the church for trying to impose it on monastic houses. There is also evidence that the threat of attack from Wales was far greater at certain periods in the seventh and early eighth centuries. The Welsh poem celebrating Cynddylan’s attack on Wall or Lichfield has already been mentioned (see page 65). According to Felix’s Life of Saint Guthlac, between 704 and 709 the ‘Britons, the dangerous enemies of the Saxon race, were oppressing the nation of the English with war, pillage and devastation of the people.’ The Welsh Annals which recorded Offa’s invasions also tell how in 722 ‘the Welsh won three battles,’ and in 743 and 753 Aethelbald of Mercia and Cuthred of Wessex fought together against the Welsh. Unfortunately we are not told the location of any of these encounters, but the one fought at Hereford in 760, at the beginning of Offa’s reign, shows that they need not necessarily have been on the western side of the frontier. In conclusion, then, it would not be surprising if Offa turned out to be only the last and best known of a succession of Mercian kings who built or strengthened earthworks along the Welsh frontier.

  Offa’s Towns

  One of Offa’s main strategic objectives in his campaigns in Kent and Sussex was undoubtedly to safeguard his occupation of London, which by the end of the eighth century was once again the principal port and market of southern England, as it had been in Roman times. But the political heartland of Mercia remained where it had been in Penda’s day, between the Birmingham Plateau and the Middle Trent Valley. The town of Tamworth, at the confluence of the Rivers Tame and Anker, lies about seven miles south-east of Lichfield and the same distance due east of Wall, and seems originally to have been known as Tomtun, a centre for the people referred to in the charters as the Tomsaetan or ‘settlers by the Tame’. It may have been a Mercian royal estate as early as the 690s, as a document of that date from Peterborough records King Aethelred confirming a deed ‘in his chamber in his own vicus called Tomtun’ (Gelling). At this date it may have been just one of several places where the Mercian kings held their courts, but by the reign of Offa it was becoming the principal base for the festivities at Christmas and Easter, and from the 780s onwards Offa regularly issued his charters from there. In 781 the name of the town appears as ‘Tamouorthige’, incorporating the element ‘worth’ which is often thought to denote an enclosed or fortified settlement (Gelling). This suggests that the ditch and bank which has been partially excavated around the centre of the modern town was constructed by Offa in recognition of its growing importance. There is little or no evidence of trade or of a substantial civilian population, but it has been deduced that there must have been a church on the site, as an ostentatiously Christian king like Offa would hardly have spent the two most important festivals of the Christian year in a place where there was no opportunity to attend mass.

  Another sign of the importance of the site is the discovery of a pair of eighth- to ninth-century water mills on the River Anker, which, as archaeologists have discovered from traces of grain, were used to grind oats and barley. Barley was the most common grain for bread making in the Anglo-Saxon period, but oats, although undoubtedly eaten by the poor, are unlikely to have been intended for human consumption at a royal palace. They may therefore indicate the presence of a large number of horses for use by the army, which had to be stabled within the enclosure and fed over the winter. Millstones have been excavated which seem to be made of volcanic stone from the Rhineland, possibly the ‘black stones’ which Offa is recorded as requesting from the Frankish emperor Charlemagne. Unfortunately no trace of Offa’s ‘palace�
� has yet been found, and it may lie underneath the present site of Saint Editha’s Church in the centre of Tamworth. It is likely in any case to have been built of wood, and many writers have envisaged something like Hrothgar’s great mead hall in Beowulf, a poem which may have been first performed at Offa’s court: ‘a house greater than men on earth had ever heard of’. Its fate, too, may ultimately have been the same once the days of Mercian glory were past: ‘Boldly the hall reared its arched gables; unkindled the torch-flame that turned it to ashes.’

  Much debate has centred around whether or not there were ‘towns’ in eighth-century Mercia, in the sense of organised communities with citizens engaged in occupations other than agriculture or government. There were, however, certainly substantial walled settlements which functioned as collection points for tribute and taxation, supply bases and probably as muster points for the army. Apart from Tamworth, Offa had such bases at Hereford, Stafford, Northampton and possibly elsewhere. Hereford was defended by a ditch similar in construction to that at Tamworth, while at Northampton traces have been found of a solidly built stone hall, one of the very few secular stone buildings in the country, the interior of which may once have looked similar to the Church of All Saints at Brixworth (see page 126). The settlement at Wall near Lichfield, where Penda may have had a similar base, is not heard of after the seventh century and may have been abandoned in favour of Saint Chad’s foundation a few miles away, although a large number of archaeological finds from the site have yet to be published. Two other former Roman cities, Chester and Lincoln, still stood at the northwestern and north-eastern corners of Mercia respectively, although in the early tenth century the walls of Chester seem to have been too dilapidated to be effective for defence. Lincoln had once been the capital of the independent district of Lindsey, a bone of contention between Mercia and Northumbria, but by Offa’s reign it was firmly attached to the former, and Henry of Huntingdon quotes an anonymous verse which celebrates Lincoln as ‘a noble city . . . facing the south’.