It is also clear that the Mercian die-cutter did not recognise the patterns on the coin he was copying to be a form of writing, much less understand it, perhaps thinking it was merely decorative, as the coin bears the inscription “ There is no God but Allah alone without equal, and Muhammad is the Apostle of Allah ” albeit with a number of mistakes. It also features the date of issue of the coin being copied -ah 157 or 773-4 CE - in the very middle of Offa’s reign, suggesting the parent coin itself was surprisingly new when it was plagiarised.

The gold coins in general circulation around Europe and the Arabic world at this time included:
- The Byzantine solidus, struck in Constantinople. Also known as the nómisma or ‘coin’ or the ‘bezant’, and first issued on a large scale by Constantine the Great. Each coin weighed 24 Greco-Roman carats* or about 4.5g (Porteous, 1969) and in theory was pure gold but in practice, the coins were often about 23 carats fine (95.8% gold). Imperial law forbade the export of these coins outside Byzantine territory, though this was only partially successful, as evidenced by finds of solidi all across Europe. Amazingly, the solidus maintained its weight, size and purity essentially unaltered until well into the 10th century.
- The Lombardic Beneventan solidus, struck in the Lombard duchy of Benevento in southern Italy. Initially similar to the Byzantine coin, it soon became debased and ended up not just inferior in purity but in weight, so that it was worth less than half the value of the Imperial coin.
- The Arab dīnār, which began as Arabic copies of solidi . These were first issued by the caliph Abd al-Malik (685–705 CE), who had access to Egyptian supplies of gold from the upper Nile (Porteous, 1969). As the Arabs had no equivalent “Byzantine” taboo on the spread of their coins beyond their territory, the dīnār began to circulate widely in areas outside of the Byzantine Empire's "currency area". In theory, a dīnār weighed 1 mithqāl (4.25g) but actually corresponded in weight to only 20 carats (4.0g); matching the weight of the old worn solidi that were circulating in those areas at the time.
- The Arab ruba'i, or quarter-dinar, which in the Christian world was referred to using the alternative Arabic loanword ‘ṭarī’, and weighed 1.05g of gold (Watson, 2002). These were minted by the Emirate of Sicily who (unlike the Muslim rulers of North Africa) found smaller lower-value coins more practical.
- The Lombardic and Frankish tremissis (or tremis) struck by the last Lombardic kings in the 8th century, and by Charlemagne. Its name, meaning ‘a third’, indicated its value relative to the solidus. Introduced into Roman currency in the 380s CE by the Emperor Theodosius I it initially weighed 1.52g.
- The Frankish ‘Pseudo-imperial’ solidus (or soldus) struck by Louis the Pious, King of the Franks and co-emperor with his father, Charlemagne, from 813 CE.
(* The ‘carat’ is a unit of weight derived ultimately from the Greek ‘kerátion’ meaning a carob seed. When in 309 CE the emperor Constantine the Great first minted the new gold solidus, it weighed 1/72 of a libra (Roman pound) and equal to the mass of 24 siliquæ (which were small thin silver Roman coins of the 4th century). The name siliqua derives from the siliqua graeca – the carob seed.)
The flow of so many different currencies with different values through territories around the Mediterranean, and particularly 8-9th century Rome, demanded contemporaneous use of a range of specific names; aurei, solidi, bizanti, mancus(s)i and solidi mancus(s)i, and in dealings with the church in Rome, Anglo-Saxon courts would certainly have needed to be familiar with these terms. Of these, aureus can mean any gold coin; solidus can mean either a gold coin or its equivalent value (i.e. 30 silver pennies), while bezant refers to the Imperial Byzantine solidus. Of these, however, it is “mancus” which appears particularly to have taken root in middle-to-late Anglo-Saxon England to refer to gold coins.
Anglo-Saxon kings and moneyers were certainly aware of many of these exotic coins, and the idea of gold currency was certainly not new or foreign to them: Anglo-Saxon kingdoms had been collecting and making use of Frankish tremisses since at least the end of the 6th century (most famously evidenced by the collection of Frankish coins in Sutton Hoo Mound 1) and some - particularly Kent - had been minting their own versions (thrymsa / scillingas) during the early 7th century. The modest ‘gold boom’ represented by the abundance of gold adornments in high status c7th burials and in the Staffordshire Hoard is attributed to a series of waves of foreign gold coinage and scrap reaching lowland Britain- in most cases Frankish, but in at least one instance Byzantine, as evidenced by the otherwise inexplicably high purity of a small handful of items within the Hoard (Fern et. al, 2019). Anglo-Saxon access to foreign gold appears to have dried up toward the mid 7th century, however, as evidenced by the increasingly sparing use of gold in jewellery, its declining purity, increasing use of silver, and the abandonment of gold coin production in favour of a system entirely focused on silver sceatta.
Offa’s dinar is an extremely rare example hinting at an 8th-9th century revival of interest in producing gold coins in England, albeit an extremely limited scale, alongside significant changes to silver currency with the introduction of the Carolingian-inspired penny. Other examples of gold coins struck in parts of lowland Britain of similar weight include the ‘Mancus of Coenwulf’ (Offa’s but-one successor) found in Biggleswade, Beds, in 2001. Around the same time Northumbria - whose principle coinage was the small silver/copper ‘stycca’ (from Old English styċċe, meaning ‘piece’) appears to have also flirted, if only commemoratively, with gold coinage, as evidenced by the unusual gold solidus of Archbishop Wigmund of York (4.39g) which may have been meant as an ecclesiastical gift rather than for circulation (Pine, 2006). In later Anglo-Saxon England gold coinage would re-emerge in the form of larger gold ‘pennies’ of Edward the Elder, Ethelred II and Edward the Confessor, weighing around 5.25g (Carradice, I, 1980).
Later accounts of Offa’s ‘Rome-scot’ refer to ‘mancuses’ but it is not clear whether Offa’s version of the dinar was referred to as a ‘mancus’ in its day. The Latin ‘mancus’ is noted in continental Europe as early as 814 CE, and appears in Anglo-Saxon texts from 848 CE until the late 11th century, and it is clear in these texts that it is understood to mean gold coinage. For example, the Welsh cleric Asser, in his Life of King Alfred refers to the will of Æthelwulf, Alfred’s father, in which he left a bequest:
“Romae quoque omni annum magnam pro anima sua pecuniam; id est treentas mancussas, portari præcepit, quæ taliter ibi dividerentur”.
"He commanded also a large sum of money, namely three hundred mancuses, to be carried annually to Rome for the good of his soul, to be there distributed in the following manner"
From this alone we could infer that Anglo-Saxons understood ‘mancus’ to refer to a high value gold coin. However, in the will of the Anglo-Saxon king Eadred, who died in 955CE, the word mancus clearly has two distinct meanings: with its request that “two-thousand mancuses of gold be taken and minted into mancuses”. Clearly the ‘mancus’ was thought of as a certain weight (of gold) as evidenced by a charter from 901 CE in which Æthelred and Æthelflæd, the rulers of Mercia, “grant land to the church of Much Wenlock and a gold chalice weighing 30 mancuses”. To these two meanings (a gold coin, and its weight in gold) can be added a third; the equivalent value in silver currency which appears to have been approximately 30 silver pennies.
Beyond its earliest use to refer to coinage, the etymology of “mancus” remains contentious. It has been suggested that it is a loan from Arabic, from the past participle manqūsh meaning ‘something engraved’. This is ingenious but scholars of Arabic in general regard the derivation of mancus from manqūsh as linguistically untenable (Ring, 2014). Alternatively, it may derive from the earlier Latin adjective mancus, whose original meaning was ‘maimed’, deriving from the Proto-Indo-European *man-ko meaning “maimed in the hand”, later gradually shifting in meaning into the early medieval period, becoming a term for anything ‘defective’. (The modern slang word “manky”, meaning worthless, rotten, or filthy, is the modern descendant.) It might be reasonable to infer that the connection with coinage referred to the “defectiveness” or low quality of circulating gold coinage, but for the fact that the two prevalent gold currencies - the Byzantine solidus and the Arabic dīnār - were generally of very high quality, so could not truthfully be described as ‘manky’ in any sense.
However, the documentary evidence clearly distinguishes between solidi of pure gold (solidi obrizi, buoni, adpretiati) and solidi mancussi. While Imperial solidi had retained their purity and hence their value, by the 8th century, coins minted in Syracuse and in Rome had not. Facing economic problems, the rulers of Syracuse and Rome did what governments in need of money and short on gold reserves have always done in such situations; they decreased the purity and weight of their coins without announcement, thus devaluing the currency; the ancient equivalent of “quantitative easing”. These solidi were now far less ‘solid’, often weighing no more than 3.5 grams and often being less than 8 carats fine (33.3% actual gold). By the end of the 8th century, Syracusian solidi were being struck at a weight 14% less than the solidus of Constantinople; 3.87g rather than 4.4g. The Beneventan solidus ended up greatly inferior not only in fineness* but also in weight, and was, apparently, less than half the value of the Imperial coin (Wroth, 1911).
(* The fineness of a gold coin represents the weight of fine metal therein, in proportion to the total weight which includes alloying base metals, such as silver, copper etc. The older carat system for denoting the purity of gold is by fractions of 24, such as "18 carat" for an alloy with 75% (18 parts per 24) pure gold by mass.)
It was thus suggested that it was these deficient, light-weight coins which coined the term ‘solidus mancusi’ (Grierson, 1954). Although by the 9th century the supply of Italian manufactured mancuses had dried up, by then the word had become established as synonymous with all gold coinage, or, more precisely, of gold coins of a certain weight or as a currency of account in silver.
With respect to "Offa's Mancus", exactly why King Offa of Mercia should have ordered the striking of such a peculiar gold coin will probably remain a mystery. Certainly we know enough about this figure’s emphatic Christian affiliation, that it is most unlikely that he had become a convert to Islam. It cannot have been an attempt at forgery given, apart from the mistakes, the ruse is foiled by the inclusion of Offa's name. If this mancus was a single example of coins Offa planned to use for overseas trade, simply copied from the dominant coinage of the Mediterranean world to lend them legitimacy without understanding the significance of the Arabic script, it is strange that only one such coin has survived. It thus seems more likely that this was a “limited edition” minting and, despite its unusual design, was intended to be gifted to the Pope. The fact that it eventually turned up in Rome in 1841 CE, does seem to add a little weight to this hypothesis. Whatever the truth, the coin remains a beautiful and tantalizing artefact, showing that the world of the distant late 8th century was complex and interconnected in surprising ways.
Carradice, I. (1980). Scripta Nummaria Romana: Essays presented to Humphrey Sutherland., (pp. 212-214.).
Fern, C., Dickinson, T. & Webster, L. (2019). The Staffordshire Hoard: An Anglo-Saxon Treasure. (p 125-127).
Grierson, P. (1954). Carolingian Europe and the Arabs: the Myth of the Mancus. Revue belge de philologie et d'histoire, 32(4), , 1059-1074.
Pine, E. J. (2006). "The Coinage of Northumbria, 670-876". Coinage And History in the North Sea World, C. AD 500-1250: Essays in Honour of Marion Archibald. . Brill. p 216.
Pelteret, D.A., (2007). Anglo-Saxon Charters Series: “Electronic Sawyer”. Old English Newsletter, 41(1), p.13.
Porteous, J. (1969). Coins in history. Putnam.
Ring, R. (2014). The Missing Mancus and the Early Medieval Economy. In Where Heaven and Earth Meet: Essays on Medieval Europe in Honor of Daniel F. Callahan. 33-41.
Stenton, F. (2001). Anglo-Saxon England.
Watson, W. (2002). Europe and Islam: Cardini, Franco: Trans. Caroline Beamish Oxford:. Blackwell Publishers, 238 pp., Publication Date: June 2001.
Williams, G. (2008). Early Anglo-Saxon Coins. Shire Archaeology.
Wroth, W. (1911). Catalogue of the Coins of the Vandals, Ostrogoths and Lombards: And of the Empires of Thessalonica, Nicaea and Trebizond in the British Museum. order of the Trustees of the British Museum.