Pop quiz, hotshot. The last King of England who went by the name of Edward was Edward VIII (1936). So, how many King Edwards has England had?

Ha. Fooled you. It's eleven.

There were no fewer than three King Edwards before the Norman Conquest of 1066 who we, vexingly, do not bother to number. Exactly who is the first king of England is harder to pin down than one might think – but if you read any list of English monarchs chronologically, you will eventually arrive at a king who is referred to as Edward I, but who is at least the third, and more probably the fourth, king Edward you come to.

Nor are these early Teddy boys minor monarchs. Alfred the Great's son, Edward the Elder (899-924), was a key figure in England's early history, leading the fight back against the Viking invaders and helping to consolidate it into a single kingdom. He didn't quite finish the job, but he styled himself "King of the Anglo Saxons" and did rule for a quarter of a century. And yet, we don't number him.

Edward the Confessor (1042-1066) also ruled for nearly 25 years, and was for some time England's patron saint. What's more, unlike his great, great grandfather you've almost certainly heard of him because of the way he mucked up his own succession, cleverly snuffing it in such a way that he set the scene for the Norman Conquest. This was not ideal from a dynastic point of view, but it nonetheless strengthens his claim to being a proper King of England who we should probably count properly. And yet we don't number him either.

To be fair, the third forgotten Edward has the unpromising name of Edward the Martyr (975-978), which tells you everything you need to know about what his main achievement as king was. But we still number Edward V, who was never crowned, was "king" for a matter of weeks, and is also famous mostly for being slaughtered by a close relative. Why does the latter get a number while the former doesn't? Where's the justice, eh?

England didn't start consistently numbering its kings until some time in the Tudor era: for a long time, monarchs were distinguished by labels rather than numbers. William the Conqueror (or, less flatteringly, William the Bastard) was followed by his son William Rufus. Other early monarchs revelled in such names as Edgar the Peaceable, Edmund Ironside and, most famously, Athelred the Unready.

At some point, though, people seem to have started switching to numbers. The fact three Edwards ruled in turn between 1272 and 1377 meant that, even in some chronicles published in his own lifetime, the last of these was referred to as Edward III. (A matter, one assumes, of convenience.) These numbers stuck, when a standard numbering began to appear some time in the 16th century - though whether this was because they were already in use, or because the Tudor chroniclers consciously decided to start counting at 1066, is not exactly clear.

To make matters worse, at least if you're a slightly anal history nerd like me, some later writers decided to impose numbering on the other kings whose names appear more than once before the Conquest. There's an Edmund I (939-946) and an Edmund II (seven months in 1016); a Harold I (1035-1040) and a Harold II (10 months in 1066; second time was not, it seems, lucky). The result of this is that we have a standardised numbering scheme on either side of the conquest, except for the one minor point that there have been 11 kings of England called Edward and we only number eight of them.

England is not the only kingdom whose numbering has gone skew wiff, of course. In France, Louis XVI (1774-1792) was followed, after a fairly eventful gap, by Louis XVIII (1814-1824). The number XVII was reserved, rather pathetically, for the former King Louis's young son, who nominally ruled from a revolutionary prison cell for two and a half years before dying of scrofula.

With similar logic, there's an emperor Napoleon I (1804-1815), and a Napoleon III (1852-1870), but Napoleon II never got to rule anything, despite the fact his father spent three days pretending that he'd abdicated to let his son have a go (and not, as in reality, because of a massive coalition army that had twice now kicked the crap out of him).

Meanwhile, Scotland is today ruled by Elizabeth II (1952-), despite the fact she's the only Queen Elizabeth it's ever actually had. Scotland never had a Queen Elizabeth I, a monarch whose main achievement in Scotland was to imprison and execute its actual queen, in the form of her cousin Mary. (Nice girl.)

This looks at first like yet more evidence of English imperialism at work, but there is at least some logic in it. When Elizabeth came to the throne, Winston Churchill, then the Prime Minister, told the Commons that, in the event of a clash of numbers, we'd use the higher one, to prevent future historians from getting confused. This makes a certain sense I suppose, but it does mean that, in the event of a James somewhere down the line, England will jump from James II to James VIII, and that'll be incredibly irritating too.

While we're at it, the United Kingdom has had not one but two kings called Albert. Only we don't call them that, we call them Edward VII and George VI. Why do we do this strange thing? Because to do otherwise might upset the ghost of Queen Victoria. No, that's honestly the reason.

Anyway, to sum up, I think it's clear that this is the real cost of keeping the monarchy.

Don't even get me started on the Papacy.

This article is part of the New Statesman's Monarchy Week. Find more here.