The economic achievements of the ‘Mercian Supremacy’ between 716 and 821

By Marcus Wells - History Student @ St Peter's College, Oxford


In 716, Aethelbald became King of Mercia, inheriting overlordship of Middlesex, Surrey and the Hwicce. Expansion under himself and his successors, Offa and Cenwulf, resulted in Mercia gaining overlordship over Sussex, Kent, East Anglia and, to a varying extent, Wessex. This political hegemony has been referred to as the ‘Mercian Supremacy’, and allowed the three rulers of the period to achieve real change in Southumbrian Britain. The economic effects of this included wider trade, both domestic and foreign.

Mercia engaged more seriously in continental trade than any other English kingdom of its day, and this trade grew throughout the eighth century. Coin finds reveal strong trade links with Frisia. Around 350 coins have been found in a hoard at Aston Rowant, Oxfordshire, from c710, roughly three-quarters of which were from the Rhineland. John Blair argues that this likely indicates Frisian merchants sailing up the Thames to trade directly in the Mercian heartland, likely seeking the raw materials deposited there, such as salt at Droitwich or iron from the Forest of Dean. David Hinton tells us that a series of ‘sceattas’ (in use from c680 to c760) have been found in the Low Countries, the Rhineland and Denmark. These reciprocal finds attest to mutual trade between Mercia and the continent in the first half of the century, and the volume of coins at Aston Rowant implies that this was on a significant scale.

There is also evidence of Offa’s trading with Francia. Frankish coins have been found in the core of the Mercian kingdom, including a silver denier of Pippin the Short (Frankish king 751-68). The coin was minted at Verdun: Hinton speculates that, since Verdun was a slave-trading hub, Offa may have traded Frankish slaves in exchange for, probably, raw materials. Charlemagne’s letter to Offa in 796 sheds further light: it allows English merchants the protection of Frankish law when in Charlemagne’s territory, and expects the reverse to apply in Offa’s lands. This shows that Mercian trade with Francia was significant enough to warrant an informal treaty on the subject and that it was of enough value to warrant legal arrangements to secure it.

However, Hinton notes that Mercia was less successful trading with Francia: despite what they can tell us, coins finds such as that at Repton are rare, even at emporia such as Southampton where imports from Francia presumably arrived, which implies a trade deficit against Mercia. Additionally, Charlemagne and Offa imposed mutual embargos when negotiations for a marriage between the two families failed, thus limiting the economic impact of Frankish trade. Even so, this indicates that the volume of trade was significant enough for an embargo to be a worthwhile sanction (trade had clearly been restored by the time of Charlemagne’s letter in 796), and the Mercian economy was evidently strong enough by the 780s to withstand an embargo. Thus, foreign trade was largely a success under Mercian kingship at this time. However, it is unclear the extent to which this was a royal achievement: the evidence makes it possible, if not probable, that it was enterprising merchants who established these connections, and kings later harnessed this trade once it was significant. This, combined with some evidence that royal intervention could be harmful, as in the case of Offa and Charlemagne, limits its significance as a royal achievement.

The Mercian kings of this period had real success in developing and harnessing domestic trade. This is most clearly indicated by coinage. Hinton’s analysis shows that many coin hoards have been found near transport routes: the aforementioned Aston Rowant, for example, lay near the Icknield Way, while ‘sceattas’ have been found near the Thames in Oxfordshire. This implies that both routes carried domestic trade: Blair posits that raw materials, wool and slaves from Mercia were transported to the emporia at London (via the Thames) and Ipswich (via the east-west Icknield Way). That the evidence for trade here is coinage demonstrates that Mercian kings were able to harness this trade, since John Campbell notes that Mercian kings likely took a cut from the minting of coins. Offa reformed the coinage of the realm early in his reign, producing new, uniform, silver coins with the king’s inscription. Inscribed coins were novel in this period, although Offa was not quite the first to implement them; their use tells us that, by Offa’s time, Mercian kingship had successfully harnessed the monetary economy to an unusual extent. Nicholas Higham and Martin Ryan note that the number of mints seems to contract after c750 to just 6: it is difficult to believe that this occurred without royal oversight, again suggesting royal control. However, as Hinton has argued, coin finds are scarce post-750, presumably because the new pure silver coins were too valuable for ordinary people. Thus, Offa and his successors clearly controlled what monetary economy there was, but this may have been restricted to mercantile activity, rather than ordinary everyday transactions.

There is also evidence that kings used tolls to harness the growing trade. Aethelbald granted by charter in 733 a toll exemption for one ship at London for the church of Rochester. This implies that, in London at least, kings were taking tolls from ships. London was a developing emporium of foreign trade in the eighth century, so it seems probable that, by 733, Mercian kings had successfully harnessed this trade through the collection of tolls. The charter also refers to “kings or nobles or tax-gatherers” as those who might infringe the charter by tolling the ship; that there were tax-gatherers suggests an organised approach to royal control of trade. Thus, the control of trade through currency and tolls was a clear economic success of eighth-century Mercia.

Eighth-century Mercia achieved much economic change. Coin-based evidence suggests reciprocal trade with Northern Europe, and a significant volume of trade with Francia. However, it is clear that Mercia was the poorer relation in the latter partnership, and the origins of these changes may well lie in mercantile rather than royal achievements. The kings also controlled much of the monetary economy to a degree new to Anglo-Saxon England, shown by the evidence of coinage and royal tolls. However, the scope of this was likely restricted to long-distance trade, both domestic and foreign. The Mercian kings did, however, succeed in increasing the volume of trade they controlled, and the extent of control they exercised.

Further Reading:

1. C. Wickham, The Inheritance of Rome: A History of Europe from 400 to 1000 (2009)

2. D. Hinton, Archaeology, Economy and Society (1990)

3. English Historical Documents c. 500–1042, ed. D. Whitelock, 2nd edn (London, 1979)

4. J. Blair, Anglo-Saxon Oxfordshire (1994)

5. J. Campbell ed., The Anglo-Saxons (1982)

6. N. Higham and M. Ryan, The Anglo-Saxon World (2013