On this date in 1402, a Prussian commoner was put to death on the road between Falsterbo and Skanor in Sweden for masquerading as the long-dead King Olaf IV.

The real Oluf IV Haakonsson — or Olav, or Olaf — had inherited the crowns of Denmark and Norway and a claim to that of Sweden’s but died at the age of 17 in 1387. His mother, Margaret I (or Margrethe I), the real power behind the teenager, ruled outright upon her son’s death.

She proved an able hand and far-sighted ruler, cautiously welding Denmark, Sweden and Norway into the Kalmar Union that would hold until the 16th century. They called her “the Semiramis of the North,” centuries before Catherine the Great nicked the nickname.

But her son’s youthful demise had set persistent rumors abroad — that he was poisoned, for instance, and more to the point for our purposes, that he wasn’t dead at all.

So when his spitting image was recognized, and hailed as the prince of the realm … well, back in the day, equally audacious identity theft was attempted for much smaller stakes than a throne.

Anyway, “Olaf” got some robes befitting Olaf’s station and banged out some letters to Margaret demanding his kingdom back, and Margaret said, come on down.

That goes to show how far looks will take you in life.

Unfortunately for Olaf, his regal jawline wasn’t capable of enunciating Danish speech … so the jig was up as soon as he got to Margaret. One hopes he got a good ride out of his brief masquerade, because he was burned to ashes — possibly after being broken on the wheel — along with those presumptuous letters.

The date of False Olaf’s death comes from Horace Marryat’s 19th century Scandinavian travelogues, One Year in Sweden; including a visit to the isle of Gotland and A Residence in Jutland, the Danish Isles, and Copenhagen (both free reads at Google Books). In both volumes, Marryat identifies the date as the morning before Michaelmas.

The traditional last day of the harvest season celebrated on September 29, Michaelmas was once a four-star holiday on the medieval calendar.

There’s a fair amount of commentary online saying that an “Old Michaelmas” used to be celebrated on October 10 or 11. But that looks to this writer like an interesting inversion stemming ultimately from the celebration’s fall into obscurity as the entity once known as Christendom has become more secular and less agrarian — although it’s admittedly nothing to do with the fate of False Olaf, or Semiramis for that matter.

In 1752, when England finally switched to the Gregorian Calendar, the switch took place in early September.*

For logistical pragmatism (the harvest wasn’t going to come in 11 days earlier just because the calendar changed), the then-imminent Michaelmas got pushed back 11 days to October 10. October 10 then became known as “Old Michaelmas,” no longer Michaelmas by the church calendar but the 365-day interval from when it used to be celebrated, and more importantly, the real end of the harvest season.**

In the next century, the difference between Julian and Gregorian calendars would have advanced to 12 days, placing Old Michaelmas on the 11th; by this present day, it’d be 13 days in principle, but the original meaning of the holiday and the host of cultural traditions associated with it have fallen away … so “Old Michaelmas” is a footnote still pinned to October 10th or 11th, and moderns rediscovering it suppose from the name that it’s the former date of the feast.

* People inclined to think of their death dates as foreordained in heaven’s celestial notebook protested the switch: “give us back our 11 days!” This reform, incidentally, also moved the official beginning of the New Year to January 1 from Michaelmas’ springtime “Quarter Day” counterpart, March 25; winter dates from years prior are often written with both years, e.g. 1738/9. “Old Lady Day“, April 6, is still the beginning of the fiscal year in England, and Thomas Hardy uses its traditional contractual character in Tess of the D’Urbervilles (Aside: Tess’s hanged real-life inspiration) when the title character takes a farm job running through that date:

Tess was so wrapt up in this fanciful dream that she seemed not to know how the season was advancing; that the days had lengthened, that Lady-Day was at hand, and would soon be followed by Old Lady-Day, the end of her term …

At length it was the eve of Old Lady-Day, and the agricultural world was in a fever of mobility such as only occurs at that particular date of the year. It is a day of fulfilment; agreements for outdoor service during the ensuing year, entered into at Candlemas, are to be now carried out. The labourers — or “work-folk”, as they used to call themselves immemorially till the other word was introduced from without — who wish to remain no longer in old places are removing to the new farms.

… With the younger families it was a pleasant excitement which might possibly be an advantage. The Egypt of one family was the Land of Promise to the family who saw it from a distance, till by residence there it became it turn their Egypt also; and so they changed and changed.

** Residents of the former Soviet Republics who switched to the Gregorian calendar in the 20th century still celebrate both the familiar January 1 New Year’s and “Old New Year’s” 13 days later, and the same trick with the (lesser, there) holiday of Christmas too … packing four party occasions into a three-week span.

Part of the Themed Set: Semiramis.

On this day..

• 1691: Johannes Fatio and the leaders of the 1691er-Wesen
• 1852: Eduardo Facciolo Alba, Cuban patriot
• 1956: Melvin Jackson, by calculus
• 1654: Hieronymus Duquesnoy the Younger, sculptor
• Daily Double: Felix Platter's Diary
• 1554: A handsome young man from Montpellier
• 1620: Sidonia von Borcke, the sorceress
• 1529: Adolf Clarenbach, Lower Rhine evangelist
• 1926: Sataro Fukiage, serial killer
• 1637: William Schooler and John Williams
• 1832: Lucy (Wells), jealous slave
• 1987: Mehdi Hashemi, Iran-Contra whistleblower
• 1898: The Six Gentlemen of the Hundred Days' Reform