How to debase the coinage in order to pay for wars

Henry VIII, after Hans Holbein the Younger

It's fun to imagine traveling back in time and engaging with the then-prevailing technologies. Would you be able to ride a boneshaker or use a counting board? It's probably harder than you think: kids today can't even use a 1980s rotary phone. In this post I'm going to write about one specific techno-institution, the mint, and a particular function that it sometimes played many centuries ago; funding wars.

If you had to go back to 16th century Europe, and you were asked to operate the mints in a way such that they raised enough revenues so that your patron, the king, could wage war against a neighbouring country, how would you go about that?

I think the general sense that most of us have is that you'd need to somehow "debase" the coinage. The majority of coins back then were made of precious metals. If you could sneakily remove some of the silver and gold from each coin, and replace it with cheaper copper, then you'd be able to amass a hoard for the king (albeit at the expense of the public), and he could use that to hire an army.  

Now, if you went back in time with the above hazy notion of debasement, you wouldn't have much luck, and might even get your head chopped off. There's a grain of truth to it, but much of it won't work.

So before you head off in a time machine, here's what you need to know about the business of minting.

The first thing you need to know is that the King (or Queen) owns the royal mints, which they rent out to private parties to operate. Another important fact is that the public brings their own personal supply of precious metal – raw silver, silver cutlery and dishes, old coins, etc – to the mint, and then after waiting a week or two for the order to be processed, walks out with the final product; newly-minted coins.

But the mint's customers don't leave with as much silver (or gold) as they arrived. For each ounce of precious metals that gets minted into coin, the King collects a fee, known as "seigniorage", usually around 5% in the case of silver. The private individual who runs the mints gets a much smaller cut too, called brassage.  

If you're scrambling for a modern analogy, I suppose you could think of the medieval business of minting as very much like a modern laundromat, where customers bring their clothes, have them processed, and leave with their clothes, paying a small fee to the laundromat owner, who in turn pays a big chunk of this to the franchisor.

Like a laundromat owner, the monarch would have earned a fairly steady stream of revenues from their mints. Coins were more useful and liquid than raw silver, so there was an ever-present demand to convert raw silver into coin for transactional purposes. But remember, the challenge you face isn't just to generate regular profit. The king wants a massive surge in revenue. He's got a war to wage. How are you going to repurpose the mints to provide this gusher?

Your first attempt to raise money for the king might be to boost the minting fee from the low single digits to 20-25%. That might work. And you wouldn't be the first to go this route. For centuries, the English seigniorage rate on silver typically hovered around 5%, as illustrated in the chart below from a paper entitled The Debasement Puzzle, by Rolnick, Velde, and Weber. For gold, the minting fee was typically at 0.5% to 2%. To help fund his war against the Scots and the French, Henry VIII raised the seigniorage on silver to a remarkable 50-60% in the 1540s. Gold fees skyrocketed to 15%.

Source: Rolnick, Velde and Weber [pdf]

Mind you, fee hikes alone aren't going to work. Dissuaded by sky-high costs, many people will stop bringing their silver and gold to the mint to be coined, and the King's seigniorage revenues will dry up. A bothersome coin shortage will probably develop, too. Off with your head! says the King.

After thinking about it some more, you realize that, like a modern laundromat owner keen to make more revenue, you need to dramatically increase the amount of material going through the mint. How to do so?

You've got a few levers to increase throughput. One option is to introduce new products. If you offer new denominations of coins, for instance, people may bring more silver to the mint because those denominations are useful to them.

There's certainly precedent for that. To help pay his armies, Henry VIII brought back the testoon, a coin worth 12 pennies (or a shilling) in the hope that there would be significant demand for them, and that this would boost throughput and thus mint revenues. Testoons complemented Henry's silver halfpennies, pennies, groats (4 penny pieces), and sixpence (six pennies), in addition to a range of high denomination gold coins.

Below is an example of one of Henry's testoons, first minted in 1542. Because they had so much copper in them (more on that later), many of the testoons that exist today have a greenish tinge (due to copper oxidation). In the 1540s, Henry VIII's silver coins still hadn't turned green, but had a reddish tinge, which tended to reveal itself on his nose. Which is why Henry's nickname was Old Coppernose.

English groat (4 pence) issued 1547-49. Source: The British Museum

But introducing new denominations probably isn't going to generate a huge rush to the mints, since a new denomination will to some extent cannibalize existing demand for other denominations. Anyone who orders more testoons is likely to order fewer groats, for example. You'll have to do more.

In addition to introducing new coins, another strategy you might try is to cancel old ones. By having the King demonetize a popular coin, or declare it to be "no longer current," those coins will cease being legal tender or acceptable for taxes. The public will be forced to bring their demonetized coins to the mint to be converted into legal coins, the rush to do so creating a revenue windfall for the King.

And indeed, Henry VIII's successor Edward VI (who continued his father's wars) did this exact same move in 1548, declaring the testoons his father had reintroduced just four years before to be no longer current, as recounted in a paper by C.E. Challis (1967). I've clipped the relevant part below:

The demonetization of testoons is announced. Source: C.E. Challis

But we still haven't broached the main method: debasement. This is where the gusher begins.

Together with the King, you announce to the public that anyone who brings precious metals to the mint will now get more coins than before, for the same weight of precious metal. So for example, if someone used to be able to bring, say, 10 grams of pure silver to the mint and got 100 pennies minted, now they can bring 10 grams and get, say, 200 pennies. Same amount of silver, more coins.

As the operator of the mint, you could enact this change by cutting the weight of each penny by half, or, if you wanted to be more clever, maintain the same weight but reduce its fineness by 50%, by introducing more cheap copper to the mix. Either way, you've just debased the currency.

But how exactly does this raise revenues for the King?

Let's think about this change from a merchant's perspective. Say that our merchant owes a supplier 1 pound (a pound is 240 pennies). He's about to pay his debt off with everything he has, 240 pennies, when the debasement is announced. He can now bring his 240 pennies to the mint and have them recoined into 480 pennies. That allows him to pay off his debt, which is still denominated at 1 pound, and still have 240 pennies for himself. What a great opportunity! The merchant heads off to the mint with his silver.

Or imagine our merchant need to buy some property that's priced at 10 pounds, or 2,400 pennies. If he has only 1,200 pennies on hand, he can't afford it. But with the debasement having just been announced, the merchant can now convert those 1,200 pennies into 2,400 pennies and make the purchase.

Congratulations, you've created a revenue gusher! What you've effectively done is offer a short-term arbitrage opportunity to those who are paying attention, most likely the rich and well-connected, at the expense of the not-so-aware. To take advantage of a profitable situation, these enterprising individuals will immediately bring all their silver and gold to the mint. And you'll collect a toll on all that metal as it passes through.

But that arbitrage opportunity won't last forever. Debts will be recalibrated to account for the 50% decline in the penny's silver content. Prices of things like property will eventually double to reflect the new true value of the penny. At that point it will no longer be advantageous to bring one's silver to the mint to be recoined, and the revenue gusher you've created will subside.

You might try announcing debasements every few years or so, thus milking your mint's throughput on a continual basis. Too many debasements, though, and this trick will stop working, since that portion of the population that is the victim of the arbitrage you've created – the less aware – eventually wises up and protects itself by quickly increasing prices whenever a debasement occurs.

A constant series of debasements is exactly what Henry VIII and his son Edward enacted between 1542 and 1551 to keep paying their soldiers. Using data from a paper by John Munro, The Coinages and Monetary Policies of Henry VIII, I've charted out (above) how the penny's silver content changed over that time period. Going into the 1500s, an English penny contained 0.72 grams of pure silver. At the end of the Great Debasement, (the term used for Henry VIII's operations on the coinage) the penny contained just 0.11 grams of silver, constituting an 85% reduction in silver content.

We can further split out how Henry VIII's debasements were distributed between changes in fineness and changes in weight. Going into 1542, the English penny was 92.5% fine. Nine years later its purity stood at just 25% silver, the other 75% being base metal such as copper. As for weight, a penny weighed 0.79 grams in the early 1500s, but only 0.43 grams by 1551. 

These changes are illustrated in the chart below.

Thus it was diminutions in purity, not weight, that drove the biggest chunk of the penny's debasement, although weight did have a role to play.

How successful were these policies in creating a financial gusher for Henry and his son?

The charts below from Rolnick, Velde, and Weber (which I've clipped from  a second paper authored by the trio) show how the combination of mintage policies enacted in the 1540s – debasement, new testoons, and a demonetization of the testoon – led to a large influx of silver and gold to the English mints.

Source: Rolnick et al

According to Challis, the combination of these inducements, along with a big boost in fees, resulted in minting profits of £1.3 million for the two kings from 1542 to 1551. This would have paid for a big chunk of the £3.5 million in military expenditures over that same period, much more than actual taxation, which only yielded £976,000.

Of course, the final result of all this was a significant number of deaths, and what one account describes as "an episode of sixteenth-century ethnic cleansing which in its aims and implementation was not dissimilar from ...the former Yugoslavia in the 1990s or, most recently, with the Myanmar government’s actions against the Rohingya." It also caused one of the worst episodes of price inflation that England had ever seen. According to Munro, the English consumer price level rose by 123% between 1541 and 1555.

So there you have it. If you had a time machine, you now know how to go back to medieval Europe and operate the royal mints in order to fund big ticket items like wars. (Whether you should actually do so is another question.)