The Royal Mint Museum has produced two beautifully illustrated books on topics of great historical interest. Lavish colour illustration should not mislead anyone into thinking that these are no more than picture books. Nor should anyone imagine that these are just a couple of coin books. In fact, both works treat topics of the greatest interest for the identity and history of the nation.

Britannia: icon on the coin is a deeply scholarly art historical and antiquarian study, tracing the use of Britannia from its ancient origins to its present incarnation as a hugely powerful national symbol. Female personification of city-states or Roman provinces was not at all unusual, and one of the earliest manifestations of Britannia shows her in the manner of an Amazon subdued by a soldier in a Roman relief excavated at Aphrodisias, where she embodies the Roman province of Britain subjected by the Emperor Claudius. More typically, Britannia appears decorously clothed and seated in the manner of Pallas Athena or Minerva, and it is in this form that she takes her place on the coinage of Hadrian, Antoninus Pius and Commodus. Antoninus Pius extended the frontier of the Empire into southern Scotland, but the limits of the province of Britannia were soon retracted and consolidated on the line of Hadrian’s Wall.

While the Roman province only briefly extended to include even a part of Scotland, Britannia never embraced Ireland. Hibernia was, of course, known to Strabo, Pliny and Ptolemy, but it was never included within Roman Britain. Over a thousand years later the accession of the Scottish Stuarts to the English throne, combined with a renewed interest in Classicism, prompted the resurrection of Britannia as an embodiment of the united crowns of England and Scotland. From 1672 until our own day she has been a regular feature on British coinage. The accession of Victoria also allowed a happy identification between the queen and Britannia, as both emerged as national personifications. Britannia also occurred on some Irish coins, though significantly her shield – emblazoned with the Union flag on British issues – is replaced with the Irish harp. The Union flag itself first incorporated St Patrick’s red saltire of Ireland only in 1801, though even then the formulation ‘Great Britain and Ireland’, reveals that Britain and Ireland remained distinct entities. Perhaps this relationship might have been explored more fully. Is there a tragic inevitability about the way that Britain’s historic failure to understand and define its relationship with Ireland should now (2018–9) undermine Britannia’s attempts to re-define her relationship with Europa?

Eustace skilfully takes us through the evolution of Britannia on the coinage, and in other forms whether as medals, sculpture, porcelain, cartoons or painting. This is an attractive and learned book.

Objects of War: currency in a time of conflict deals with currency and war, and the links between them. Clancy’s concern is with Britain, though in passing he notes the connection in many other countries. He is careful not to overstate the case, pointing out that minor wars often leave currencies unscathed, but the devastating and transformative impact of major wars on the British financial system and currency is made clear. He also concentrates on the last five hundred years, and although medieval examples of the link between currency and war are not hard to find – Edward iii’s default and the Hundred Years’ War spring to mind – it is true that the connections become obvious in the context of the Wars of the Spanish Succession, the French revolutionary and Napoleonic wars, and in the two world wars of the twentieth centuries. The Bank of England was conceived to manage the burgeoning national debt occasioned by the cost of resisting Louis xiv, while the expense of dealing with Napoleon led both to the creation of income tax and the suspension of the right to demand gold in exchange for bank notes. The suspension of gold payments was only temporary, but the recurrence of that suspension at the beginning of the First World War is telling. The story is essentially that of money’s long march from precious metal to paper and electronic transfers, but the exigencies of war have repeatedly hastened the step from hard metal towards more flexible arrangements.

Clearly the state could only enforce its will in this way within its own boundaries. For overseas payments, governments still needed gold. It is significant that Maynard Keynes’ wartime service in both world wars concerned managing the exchanges and balancing the nation’s books. Of course, defeat in a major war destroyed a government’s authority and with it the power to guarantee its money. Issuing currency and waging war are two fundamental aspects of the state. This is obvious for waging war, but the role of the state in making, issuing, policing and enforcing the use of its currency is an even more fundamental aspect of statehood, which impacts daily on all its subjects. Indeed, it is so pervasive that it is sometimes taken for granted.

Wars are frequently paid for by credit, since the sudden requirement for money was far in excess of the government’s regular income. Clancy quotes Benjamin Franklin’s perceptive observation that ‘Wars are not paid for in wartime, the bill comes later’. He also quotes Socrates’s remark that ‘All wars are fought for money’, which is sufficiently provocative to prompt one to explore this comment further. Unfortunately, unlike Eustace’s book, Clancy’s work is not provided with footnotes. Yet there is enough insight here, and the interconnected themes of money and war sufficiently important, to suggest he might want to expand this popular treatment into a fully referenced scholarly volume.

However, this is not to disparage the value of popular treatments, which reach a less academic audience. Within the targets it set itself this is a thoughtful, challenging and stimulating book. It is beautifully and sensitively illustrated: Stephen Raw’s original artwork for Carol Ann Duffy’s poem Shrapnel is a telling reminder that the cost of war is very much more than money.