Offa of Mercia

Penny of Offa, London, moneyer Aethelwald
Penny of Offa, London, moneyer Aethelwald

Offa (died July 26/29, 796) was the King of Mercia from 757 until his death. Prior to the rise of Wessex in the 9th century, he was arguably the most powerful and successful of the Anglo-Saxon kings, effectively ruling much of Britain south of the River Humber during the latter part of his reign. Offa's Dyke is named after him.

Offa was the son of Thingfrith and a descendant of Eowa, the brother of King Penda, who had ruled over a hundred years before. Following the murder of his cousin, King Æthelbald in 757, Offa defeated Beornrad, who fled, thus seizing the throne of Mercia. Offa took over a kingdom that had enjoyed supremacy over southern England during Æthelbald's reign, but this supremacy had been seriously weakened by Æthelbald's death and the subsequent internal conflict. Offa thereafter endeavoured to reestablish Mercian power over the other Anglo-Saxon kingdoms.


Perhaps the main reason Offa has not received the same kind of attention as Alfred the Great is poor source survival from his reign. The main literary source is the Anglo-Saxon Chronicle, though this was a West Saxon production, and it may not fully convey the extent of Offa's power. That power can be seen more usefully in charters dating from Offa's reign, while the monument of Offa's Dyke, most of which was probably built in his reign, demonstrates the extensive resources Offa had at his command, and more importantly the ability to organise these. Though problematic, the document known as Tribal Hidage might be seen in this context. A significant corpus of letters date from the period, especially from Alcuin. These in particular reveal Offa's relations with the continent, as does his coinage which was based on Carolingian example.

Offa and the Anglo-Saxon kingdoms

Frank Stenton, in his Anglo-Saxon England, noted that the evidence of charters from the period suggests that Kent fell under Offa's influence. The kings Heahberht (mentioned in a charter of 764) and Egbert (mentioned in a charter of 765) were client kings subject to Mercian authority. In two charters of 774 Offa grants land in Kent without any mention of a Kentish king.

The Anglo-Saxon Chronicle records that "the Mercians and the inhabitants of Kent fought at Otford" in 776. The outcome was not recorded; it was traditionally interpreted as a Mercian victory, but Stenton noted that there is no evidence that Offa exercised any authority over Kent during the years that immediately followed the battle, and a charter from 784 mentions only a Kentish king named Ealhmund. This may indicate the possibility that the Mercians were in fact defeated at Otford, but in any case Offa was certainly exercising authority over Kent by 785, and Mercian control lasted until 796, the year of Offa's death, when a rebellion under Eadbert Praen was temporarily successful in regaining Kentish independence.

In Sussex, Offa's authority appears to have been recognized early by the local kings of its western part, but eastern Sussex does not seem to have submitted to him so readily. In 771, a war was fought which ended in Offa's imposition of his rule over the whole of Sussex by 772; the South Saxon kings were afterward known merely as "dukes".

Elsewhere, Offa won an important victory over the West Saxon king Cynewulf at the Battle of Bensington (in Oxfordshire) in 779, reconquering land that had earlier been lost to the West Saxons. In 786, after the murder of Cynewulf, Offa intervened to place Beorhtric on the West Saxon throne, possibly in opposition to a rival claimant, Egbert who had links to the Kentish dynasty that opposed Mercian rule. It seems likely that Beorhtric to some extent recognized Offa as his overlord. He married Eadburh, a daughter of Offa, in 789. Offa's currency was used across the West Saxon Kingdom, and Beorhtric only had his own coins minted after Offa's death. The border or Wessex and Mercia in this period seems to have been peaceful; recent archaeological excavations at Oxford have revealed an important Middle Saxon bridge, but no fortifications comparable to those at Hereford.

In 794, Offa took over East Anglia after the murder of its king, Aethelbert. The circumstances of this are unclear, and the Anglo-Saxon Chronicle simply states that "Offa, King of Mercia, ordered Aethelberht's head to be struck off." Roger of Wendover later gave an account of the event in which Aethelbert was killed through the treachery of Offa's wife Cynethryth, but his account may be entirely legendary.

portrait penny of Cynethryth, Canterbury mint, Eoba
portrait penny of Cynethryth, Canterbury mint, Eoba

Offa and the Welsh

Like all Mercian rulers of the period, Offa was often in conflict with the various Welsh kingdoms. There was a battle between the Mercians and the Welsh at Hereford in 760, and Offa is recorded as campaigning against the Welsh in 778, 784 and 796. He is perhaps best known for Offa's Dyke, a great earthen wall between England and Wales. It is attributed to Offa thanks to the writings of the monk Asser, though there is no firm reason to doubt this account. What the Dyke does reveal is that whoever built it had considerable resources at their command and an administrative structure that enabled them to deploy these.

European Connections

In his relations with the most powerful European ruler of the age, the Frankish king Charlemagne, it is clear that the latter recognized Offa's power and accordingly treated him with respect. In the one surviving letter between the two men, Charlemagne refers to Offa as his 'brother'. It is also evident, however, that Offa wanted to be treated not merely respectfully, but as an equal of Charlemagne, and this insistence produced some discord in his relations with the Franks. Around the year 789, Charlemagne attempted to negotiate the marriage of one of his sons to one of Offa's daughters; Offa, however, made such an arrangement contingent upon the marriage of his own son, Ecgfrith, to one of Charlemagne's daughters. Charlemagne considered this demand a serious affront, and responded by temporarily closing Frankish ports to traders from England. Charlemagne also harboured a number of English refugees from Offa, most notably Egbert, who returned to rule Wessex after the deaths of Beorhtric and Offa, and was the grandfather of Alfred the Great.

The Church

The influence of the Kentich archbishopric (Canterbury) angered Offa and he tried to get the pope to elevate the Mercian diocese of Lichfield to an archdiocese. In 787, the English episcopate consented and the archbishop of Canterbury, Jaenbert, did not protest. Hadrian I gave Higbert the pallium in 788. The Southumbrian church was divided, though by consecration, Jaenbert maintained precedence.

Offa came into conflict with Jaenbert, the Archbishop of Canterbury, and he tried to reduce the power of Canterbury through the establishment of a rival archdiocese at Lichfield, obtaining the approval of Pope Adrian I. A council at Chelsea agreed to its creation in 787, although only after some dispute. Hygeberht was made the first (and only) archbishop of this new see. The records of the papal legates who travelled to England to assess the case for a new archbishopric are among the few surviving documents on Mercian politics from the period. Wormald argues that they may reflect Offa's lost law codes, referred to by Alfred the Great.

The main advantage Offa gained by the elevation of Lichfield into the seat of an archbishop, was that it allowed him to have his son, Ecgfrith, consecrated. This followed the recent example of Charlemagne having his successor anointed by the Pope.

Offa as a "statesman"

In Anglo-Saxon England, Stenton argued that Offa was perhaps the greatest king of the English kingdoms, arguing that "no other Anglo-Saxon king ever regarded the world at large with so secular a mind or so acute a political sense". Proof of Offa's abilities was obscured by the lack of a historian (such as Bede a half-century earlier, or Asser a century later) to describe his achievements. However, some care is needed not to regard Offa's reign as just another step towards the formation of England. Offa is best considered in his 8th-century context.

portrait penny of Offa, Canterbury mint, Eadhun
portrait penny of Offa, Canterbury mint, Eadhun

Offa reformed the silver coinage in England, producing the first English silver pennies. Offa's currency reforms were prompted by, and in competition with, those of Charlemagne in Francia, which is reflected in their iconography: they carry a wide range of portraits inspired by Roman coinage and contemporary portrayals of the Biblical King David. Offa's queen, Cynethryth, was the first and only Anglo-Saxon queen ever named or portrayed on the coinage. The establishment of a new coinage is important evidence for Offa's administrative control over the economy, though there are many difficulties with the chronology and structure of the coinage: a sparse, early coinage was struck at mints in Canterbury, London and somewhere in East Anglia. Two early kings of Kent - Heaberht and Egbertalso struck coins at Canterbury around this time, probably in the 760s and 770s. This early coinage merges into the very large light coinage, which contains the celebrated portrait coins of Offa and his queen. Coins were also struck at Canterbury in the name of Archbishops Jaenbert and Aethelheard. Around the time of Jaenbert's death and replacement with Aethelheard in 792-3 the silver currency was reformed a second time: in the subsequent heavy coinage the weight standard and flan-size were increased, and a standardised non-portrait design was introduced at all three mints.

The Offa 'dinar
The Offa 'dinar'

Along with the silver pennies, a few gold coins were produced, copied from a gold dinar of the Abbasid caliph Al-Mansur dated 157AH (773-4 AD). Offa Rex is centred, though the moneyer clearly had no understanding of Arabic as the Arabic text is upside down. This coin has been cited by some as proof that Offa had converted to Islam. Others argue it is more likely that the coin was produced in order to trade with Islamic Spain or as part of a yearly donation of alms to the Pope in Rome.

Although Offa had initially used the title "rex Merciorium" (king of the Mercians), he used a multitude of titles over the course of his reign. By the end of his reign, "rex Merciorum" had been settled on as the standard. In 774 however, he is first recorded as using the title "rex Anglorum". Offa was the first king to use that title, and it has been seen as a sweeping statement of his power.

Offa's supposed use of this title has caused considerable debate among scholars. Several of the charters in which Offa is named "rex Anglorum" are of doubtful authenticity. They may represent later forgeries of the 10th century, when this title was standard for kings of England. The evidence of coins strongly suggests, however, that Offa did occasionally use the title "rex Anglorum" as an alternative to "rex Merciorum".


During the last decade of his reign, Offa exerted himself to ensure that his son Ecgfrith would succeed him. In 787, he had Ecgfrith crowned as his co-ruler. After Offa's death in July 796, however, Ecgfrith survived for only five months, dying under unclear circumstances. Offa's reign marked the apogee of Mercian power: only a quarter of a century after his death (825), the role of leading English power passed to Wessex.


  • Anglo-Saxon Chronicle, 757 to 796.
  • Stenton, Frank M., Anglo-Saxon England (1943). Chapter VII, "The Ascendancy of the Mercian Kings." Third Edition, Oxford University Press.


Preceded by:
King of East Anglia Succeeded by:
Preceded by:
Ealhmund of Kent
King of Kent Succeeded by:
Eadbert II of Kent
Preceded by:
King of Mercia
757 - 796
Succeeded by:
Preceded by:
Ethelbald of Mercia
Bretwalda Succeeded by:
Egbert of Wessex

Most of Wikipedia's text and many of its images are licensed under the
Creative Commons Attribution-ShareAlike 3.0 Unported License (CC BY-SA)

Return to Main Index