Pirates have been romanticized in popular culture for more than a century.

We get our ideas about what pirates were like from sources such as the Robert Louis Stevenson novel “Treasure Island,” the Gilbert and Sullivan operetta “Pirates of Penzance,” and the fairytale “Peter Pan.” Dozens of films portray swashbuckling men of the sea, most recently the “Pirates of the Caribbean” series.

Most of what we think we know about pirates, based on these and other popular sources, is false. Take the concept of walking the plank.