What do you think of this fact?
“Quarantine” sounds like a medical term. Hidden inside it, though, is just a number. The word goes back to the Italian “quaranta”, which means forty. The funny part: the first rule of its kind didn’t even last forty days.
It started with 30 days
In 1377, the port city of Ragusa, today’s Dubrovnik in Croatia, passed a law against the plague. According to the University of Münster, ships from plague areas had to anchor offshore for a month. Snopes, citing a 2002 article in the journal Clinical Infectious Diseases, calls this rule a “trentino”, from the Italian “trenta”, thirty. So the very first quarantine was really a “thirtyntine”.
The University of Münster writes that the 30 days were soon increased to 40, and that Marseille imposed a 40-day quarantine in 1383. Other European cities followed, and the longer period won, Snopes reports. That turned “trenta” into “quaranta”, and the name stuck. Etymonline tells a different version: it credits Venice with a 40-day wait from 1377 onward. The University of Münster and Snopes, though, start the story in Ragusa, with 30 days.
Why exactly 40?
Nobody knows for sure. Snopes lists several theories. Maybe 30 days simply seemed too short. Maybe it was a nod to Lent, the 40-day Christian fasting period, or to other forty-day stories in the Bible, like the great flood. Snopes also mentions the ancient Greek doctrine of “critical days”: a contagious disease was thought to develop within 40 days.
One root, two languages
German “Quarantäne” and English “quarantine” share this root. According to Duden, the German word came via French and goes back to Latin “quadraginta”, forty, after the 40-day lockdown for ships with suspected disease on board. Etymonline dates the English noun to the 1660s, first for the period a ship suspected of carrying disease was kept isolated.
Bonus fact: Before it meant isolation, English “quarantine” had another forty-day meaning. According to Etymonline, in the 1520s it was the 40 days a widow was allowed to stay in her late husband’s house.
So whenever someone says they’re stuck in quarantine, they’re technically counting to forty in Italian, after rounding up from thirty.