The debt of a middle-ages kingdom

Question

My setting is low-fantasy (weird stuff happens sometimes, but it's rare enough not to have a real impact on everyday life). It focuses on a specific kingdom.

This kingdom is supposed to be a typical small kingdom from the middle ages. It would be something like 10,000km² big, with a standard population.

The money unit is the denier (with bronze, silver, and gold deniers). 20 bronze deniers = 1 silver denier; 20 silver deniers = 1 gold denier. A peasant earns 1 bronze for a day of labor and something like a good meal at a fancy tavern costs 1 silver.

The kingdom has consequential debts.

What would be the total number of coins in circulation? What would be a coherent amount for these debts? What would be a plausible yearly income?

Answer 1

All of these numbers should be taken with a huge grain of salt, many assumptions and approximations have been made, without very detailed information about your kingdom's population and economic situation I think that's the best you can hope for.

Yearly income and debts

If one days labor nets 1 bronze, you could easily extrapolate a yearly income.

1 bronze a day x 6 days a week x 52 weeks a year = 312 bronze a year

Also equaling 15 silver 5 bronze. So for reference giving a gold coin to a peasant is more than they are likely to earn in a year.

Skilled craftsmen would obviously earn slightly more than this, as would land owners and other businessmen, but the peasants would be the majority of the population so this would be likely near the median income.

The Clergy and the Monarchy would of course take their cut in tithe and taxes. These were never fixed percentages of income, but mostly fixed fines/fees but generally overall were less than 10-20% of income. So a good approximation of their incomes would be a percentage of the income of the entire kingdoms population.

I'm going to make up some numbers here. Assuming a very-fertile kingdom populations could be around 10 people per square km so your kingdom would have a population of ~100,000 people. So assuming median income for 100,000 people and 10% for the king gives a royal treasury income of ~ 3,000,000 coppers = 150,000 silver = 7500 gold a year

So a debtor is unlikely to loan more than the entire treasuries yearly income, especially given no collateral, but an unscrupulous royal could engage multiple lenders. So debt could potentially be several tens of thousands of gold coins

Coins

A kingdom of your size would likely not even have a mint, but would instead use coins generally in circulation or only mint lower value coins. Following the fall of Rome western Europe didn't mint gold coins for nearly 1,000 years (until the Floren in ~1200), instead using locally minted silver coins (often adulterated with copper) and gold coins from the east. There would be no exact way to know the total coinage in circulation, and precious metals would often be stored by melting them down and making them into things. Barter or other exchange good contracts would be much more common, the peasant is more likely to be paid in food than coins.

The circulation would depend a lot on the economics and population of the kingdom, things like the velocity of money come in to play i.e. that peasant is likely to spend almost all of his earnings as soon as he gets them. So that peasant may only even see a few copper coins at a time and would often never have any coins.

Warning Many Assumption Again - So 100,000 people generally only needing a few coppers a piece would give you somewhere around only 300,000 coppers total in circulation. This clearly isn't enough money to pay the king, but again barter would be more common, The royal treasury could pay with food for needed labor, or would pay functionaries by allowing them to collect the taxes or fees for a region (i.e. the city guards are paid by collecting tolls at the gates etc.)

Answer 2

• A substantial part of the economy would be based on barter. The serf owes the lord two weeks of work at harvest time, a fat chicken at some holy day, and so on, but not a set amount of money.
• A substantial part of "cash savings" would be in coins or other small valuables like jewelry. Few people deal with bankers. Even more of the savings would be in real estate, tools, etc.

So most people have absolutely no coins, or at best a couple of dozen hidden away under the hearth. A prosperous craftsman might have a small bag of coins. Only merchants and nobility would have chests full of coins, and there are not many of them.

Answer 3

The thing about commodity based currencies is that the supply isn't fixed; one of the reasons people shifted to using metal alloys instead of actual gold and silver.
If say an enemy ship full of gold bullion was captured by your country's navy; if the government wants to boost the economy, it converts the bullion into coin and starts public works. The number of gold coin in the market increases, but there's not that much increase in demand for gold coins; the master mason isn't going to pay all his people in gold, he'll pay most in silver or bronze. He will, most likely, go to a goldsmith and trade a lot of the gold coins for silver and bronze coins. The goldsmith, in turn, can sit on the gold, or melt it down into stuff he can sell to the rich and get silver and bronze coins, which he can trade for the next batch of gold. On the other hand, if there's a shortage of coin in the market, the price of gold coins will rise on the limited supply, compared to the price of solid gold dinner plates (let's say). People will simply melt them down into coins for circulation.

Remember, the point of a Royal Mint is that the monarch's honour guarantees that each coin is of the material and weight specified, not that no other source of coin exists. That came much later.

The other issue is that the size of the economy is measured by the total value of the number of coins in circulation, and the speed at which they circulate. A small, isolated village may only have 40 silver and 100 bronze coins in circulation, but most of the bronze will probably change hands dozens of times in a day. Given that we know neither the population, nor the details of the economy, as in what shape is the treasury in, what are the major products, what kind of individual holdings are there, what do they need to buy from abroad, etc., it's not possible to guess at annual income; and given the circulation rate issue mentioned above, even if the number of coins were fixed, it wouldn't be possible to guess, unless the Royal Mint issued numbered coins as the only legal tender.