A gold penny or mancus of 30 pence of Coenwulf, King of Mercia (796-821 AD) was discovered on October 6th 2004. Found by an amateur metal detectorist, next to a public footpath beside the River Ivel in Bedfordshire in 2001, the Coenwulf gold penny was consigned to Spink by agreement with the landowner. As a single coin find, it is not subject to the Treasure Trove law. This extraordinary coin, the most important discovery in British numismatics for many years, is the first new Anglo-Saxon gold penny to come to light for almost a century. It is a significant addition to the very select group of seven gold Anglo-Sax-on pennies already known, all of which are in museum collections. These seven gold pennies survive from the three centuries from the introduction of the broad flan silver penny under Offa of Mercia (757-796) to the reign of Edward the Confessor (1042-1066). The present coin, unique as the only gold coin of Coenwulf of Mercia, unique as the only purpose made Anglo-Saxon gold penny of clearly regal design, and unique as the only gold coin from this period with a London mint signature to be struck between the gold shillings of ca. 630 AD and Henry Ill’s gold penny of 20 pence of 1257, is also the only English coin of any type to refer to the important extra-mural commercial settlement of Lundenwic. The coinage of medieval western Europe was one of silver with the exception of those parts of Christendom recovered from the Muslims. In about 670 AD, the coinage of silver deniers was inaugurated in the Frankish kingdom of Neustria, and by 700 AD silver had taken over completely in the West, a monometallism that was set to endure for five hundred years. Gold remained known, usually in bullion form, and was often available. Sums of gold were often referred to in documents and in wills, but these amounts were paid by weight, in the equivalent value of silver, or in Muslim gold coins. Only very occasionally, possibly for reasons of prestige, were gold coins actually struck. In England the term mancus, possibly derived from vanquish (engraved) an adjective used to characterize dinars in Arab records, came into use meaning an Arab gold dinar, and subsequently as a unit equivalent to the weight of gold of a dinar (4.25 grams) or the value of a dinar in silver currency, 30 pennies, at a gold to silver ratio of 10:1 The unique gold penny of Coenwulf is lot 493 in Spink’s October Coinex sale, and it is estimated to realize between £120,000-150,000.