Being sent on a “wild-goose chase” now means wasting your time on a hopeless or pointless search. But the original wild-goose chase wasn't about chasing geese at all.

In 16th- and 17th-century England, the term referred to a form of horseback competition. One rider took the lead while the others followed the same course at set intervals. The formation apparently reminded people of wild geese flying behind a leader, which gave the pursuit its peculiar name.

The sport has long since disappeared, but it left behind an expression that is more than 400 years old.

One of its earliest known appearances in print is in Shakespeare's Romeo and Juliet, written in the 1590s. During a rapid-fire exchange of jokes with Romeo, Mercutio declares:

“Nay, if thy wits run the wild-goose chase, I have done...”

Shakespeare probably didn't invent the expression. His use of it suggests that audiences already understood the reference to the equestrian pursuit.

Over time, the original sport faded from memory while the phrase acquired a new meaning. A “wild-goose chase” came to describe a fruitless pursuit or search, perhaps helped along by the rather convincing mental image of someone actually trying to chase down a wild goose.

The horses are gone. The geese were never really being chased. But more than four centuries later, we're still going on wild-goose chases.