News of  shipwrecks reached London regularly during the lifetime of William Shakespeare. The frequency of travel by water and the fragility of wooden sailing vessels made disaster at sea a relatively common occurrence. Thus it is all the more striking that the playwright chose one particular wreck—the loss of a Jamestown ship on uninhabited Bermuda four centuries ago this month—as an inspiration for his ethereal Tempest.

The Sea Venture was voyaging from London to the two-year-old colony on the Virginia coast in the summer of 1609 when it encountered an intense hurricane. After four days of punishing violence the ship came to rest on a Bermuda reef. All 153 people aboard survived to be remembered as the first to occupy the mid-Atlantic isle. A year later when some of them returned home and told their story, Shakespeare ensured they would also make literary history as a source for his last solo play.

Timing had much to do with the castaways’ unexpected foray onto the London stage. As Shakespeare neared retirement, plague had shut down the theaters and curtailed the revenue of his King’s Men players. The playwright needed a fresh story, and as usual he began by looking for a contemporary topic that might be explored in a classical setting. Few subjects were of greater interest to the people of London than England’s fledgling colony in America. In fact, the overseas ambitions of the country so dominated current conversation that it would have been surprising if the city’s leading playwright had not written them into a play. Colonial adventure would be a fine general theme, but he needed specifics, and the Sea Venture story apparently provided them.

Shakespeare certainly recognized that the Bermuda wreck was no ordinary event. The tale was thrilling—a leaking ship in an unremitting storm, a rogue wave sweeping the vessel and filling it with water, St. Elmo’s fire glittering on the masts at a time that sinking seemed assured, land sighted in the middle of the ocean to the shock of all on board, a miraculous wedging of the ship upright between coral ridges in the Bermuda shallows, nine months on a deserted isle, and the reappearance in London of castaways long thought dead. Here was a story that an inventive playwright might fashion into stagecraft that would excite the masses.

Another element that apparently attracted Shakespeare was Bermuda’s history as an enchanted isle. The magical qualities of Prospero’s island likely had their origin in stories told by generations of Atlantic sailors who heard eerie cries in the night when sailing past Bermuda. The Sea Venture castaways discovered that a nocturnal bird called the cahow was responsible for the ghostly racket. Shakespeare did not have to make too great a leap to transform the shrieks of the seabirds into the Tempest isle’s “noises, sounds and sweet airs.”

As the battered Sea Venture headed for an island grounding on July 28, 1609, the voyagers guessed that they were landing on haunted Bermuda. To their relief they soon discovered that their sanctuary was more a realm of angels than devils. The very birds that had frightened passing sailors were easy game for hunters. Giant sea turtles provided feasts of meat when they came ashore to nest. Succulent prickly pears grew on the rocky shore. Palmetto sap and cedar berries were available for fermentation. Shakespeare seemed intrigued by this aspect of the story, apparently incorporating it into his play as the spells Prospero used to hide a bucolic isle within a conjured storm.

In addition to taking possession of general aspects of the Sea Venture narratives, Shakespeare also seems to have transformed specific elements. In his nimble mind the St. Elmo’s fire that voyager William Strachey described as a “little round light like a faint star, trembling and streaming along with a sparkling blaze half the height upon the mainmast” became the luminous character Ariel. In a brilliant appropriation of Strachey’s image, Shakespeare recast the sparkling glow as a shimmering apparition who visited the Tempest ship and reported to Prospero that “on the topmast, the yards and bowsprit would I flame distinctly.”

The enigmatic Caliban also seems to have Bermuda roots. There is a peculiar passage in Strachey’s narrative that combines human and bovine imagery in a description of a sea turtle. Shakespeare joined the same three elements when he fashioned the features of his wild man, giving him arms like turtle fins and the nickname “mooncalf”—a term meaning deformed child but one evoking heifers nevertheless. Caliban’s murderous disposition may also have arisen from the stories of the returning castaways. As I show in my new book, A Brave Vessel: The True Tale of the Castaways Who Rescued Jamestown and Inspired Shakespeare’s The Tempest, there is fresh reason to believe that two Powhatans from Virginia were aboard the Sea Venture and that the English believed—perhaps falsely—that one of them murdered the other on the island.

Even small touches were apparently transferred from the Sea Venture chronicles to The Tempest. Strachey wrote of the castaways’ fermented cedar-berry drink that was brewed to replace the beer of England. The voyagers collected “berries whereof our men seething, straining, and letting stand some three or four days made a kind of pleasant drink.” Shakespeare was apparently taken with the image, for in The Tempest Caliban makes the otherwise inexplicable statement that when he was thirsty Prospero “wouldst give me water with berries in’t.”

Thus it may be said that July 28 marks two quadricentennials. One is the unintended founding of Bermuda by castaways who came ashore on a rain-whipped day in 1609. The other is the birthday of a sprite, a wild man, and a mercurial magician, characters given life when a Jamestown shipwreck captured the imagination of a literary master and inspired an enduring tale called The Tempest.