Why the Mile is Weird

If “mile” means “thousands”, why is the mile 5280 feet? Sources online are contradictory and I think tend to miss the real answer.

When King Henry III and/or Edward I (we don’t actually know which guy is to blame) standardized measurements, he chose to use a relatively long furlong and a relatively short foot. Thus contrary to existing convention, 660 feet per furlong was enshrined in law. He didn’t mention the “mile” per se, but the damage was already done.

See, the old French¹ mile was 10 furlongs of 600 Drusian feet each. Greece had a similar system. Meanwhile, the Roman Mile was 8 furlongs of 625 Roman feet each.

Typical for England, they ended up with both systems using the the same names. King Hed/ward could have enshrined either of these two into law, but he decided to invent his own instead. 625×8 gives a mile of 5000 feet (1000 paces). 600×10 gives a mile of 6000 feet (1000 fathoms). But 660? …

Why did he do this? 🤷‍♀️ Speculation: A shorter foot was used by builders as a vestige of Roman soldiers building forts², while the longer furlong was used in land surveying. King Ed/ry wanted to make as few people angry as possible and figured the ratio just wasn’t very important.

His standardization of the foot and furlong³ have lasted to the present day. Miles, remained a mess for another few hundred years.

Internet sources typically blame Elizabeth I for the 5280 foot mile, because a 1593 statute is where that definition appears in law. But:

1. Even before that, maps would sometimes have a “short mile” of 8 furlongs.
2. Had the statute used the 10 furlong “long mile”,⁴ the mile would be 6600 feet - less silly, but still silly.⁵
3. That statute was really just a clarification about zoning regulation, not a universal definition. It’s like how bees are fish in California. This article claims it was really the Postal Service which made the 8-furlong mile the default.

¶ Sources

The first two chapters of the book British weights & measures: a history from antiquity to the seventeenth century, by Ronald Edward Zupko, 1977, detail the origin of the 660 foot furlong. He notes that the original prototype yard was unlikely to be more than a millimeter off from present standards. That’s actually fairly impressive, England. Bad choice of standardization, but good job standardizing.

The article The Old English Mile by Wm. Flinders Petrie and Robertson Smith, 1884 makes a compelling case that the Old English mile was originally similar to the old French mile of 6000 Drusian feet. Flinders also wrote the Weights and Measures section of the 1911 Encyclopedia Britannica, which discusses these things a bit more.

The article A Cartographic Evaluation of the Old English Mile by I. M. Evans, 1975, goes into more detail about the chaos that was the “mile”, and is the one that blames the Postal Service for standardizing the 8 furlong mile.