“Call me Ishmael.”

Chances are, even if you haven’t read it, you know the book from which this line is taken. Commonly known as one of the canonical Great American Novel, Moby Dick, which was first published in the United States on this day back in 1851, is the celebrated tale of quest of Ahab, captain of the whaling ship Pequod, told by the aforementioned Ishmael, as Ahab seeks vengeance against the giant white sperm whale that bit off his leg on the ship’s previous voyage. It was generally panned upon its release, not finding its audience or place in literary history until well after the author, Herman Melville’s, death in 1891. Nowadays, the work is celebrated, quoted, and parodied, with the term “white whale” becoming synonymous with an elusive dream.

But the white whale, tragically, was in fact very, very real.

The novel has become so encroached in American popular culture that many do not realize the story was based on the real-life–and horrifying–experience of the whaling ship Essex back in August of 1819.

The trouble for the ship began as soon as it left Nantucket on a whaling voyage that was supposed to last two and a half years. The 87-foot-long ship was hit by a squall that destroyed its topgallant sail and nearly sank it. Still, Captain George Pollard Jr., who was just 29 years old, managed to command the ship (and its 20-man crew) all the way to Cape Horn. Finding the waters off South America nearly fished out, they decided to sail for distant whaling grounds in the South Pacific, far from any shores. After restocking in the Galapagos Islands, the ship set off once again.

The decision turned out to be a prosperous one.By November 1820, over a year since they’d first set sail, the Essex had spent months in the South Pacific, harpooning whales with fervor, dreaming of the payday awaiting them upon their return home.

One particular morning, Captain Pollard, along with several other men, left the ship in one of several smaller whaleboat, intent on joining the day’s hunt. First Mate Owen Chase stayed behind to make repairs on the main vessel. It was Chase who first spotted a very big whale—85 feet in length, he estimated—lying quietly in the distance, its head facing the ship. Then, after two or three spouts, the giant made straight for the Essex, “coming down for us at great celerity,” Chase would recall—at about three knots. The whale smashed head-on into the ship with “such an appalling and tremendous jar, as nearly threw us all on our faces.”

The whale passed underneath the ship and began thrashing in the water. “I could distinctly see him smite his jaws together, as if distracted with rage and fury,” Chase recalled. Then the whale disappeared. The crew was addressing the hole in the ship and getting the pumps working when one man cried out, “Here he is—he is making for us again.” Chase spotted the whale, his head half out of water, bearing down at great speed—this time at six knots, Chase thought. This time it hit the bow directly under the cathead. Water rushed into the ship so fast, the only thing the crew could do was lower the boats and try fill them with navigational instruments, bread, water and supplies before the Essex turned over on its side.

Captain Pollard and the other men returned swiftly but, at this point, there was nothing they could do but watch helplessly as the Essex floundered. In all, there were three 20-foot boats with 20 men spread out between them. They calculated that the closest land was the Marquesas Islands and the Society Islands, and Pollard wanted to set off for them—but in one of the most ironic decisions in nautical history, Chase and the crew convinced him that those islands were peopled with cannibals and that the crew’s best chance for survival would be to sail south. The distance to land would be far greater, but they might catch the trade winds or be spotted by another whaling ship.

Upon setting out, they were challenged almost immediately. Saltwater saturated the salvaged bread, and the men began to dehydrate as they ate their daily rations. The sun was relentless and brutal. Pollard’s boat was attacked by a killer whale. They spotted land—Henderson Island—two weeks later, but it was barren. After another week the men began to run out of supplies. It was decided their best bet was to set out into open water once again. Three of the men, however, decided they’d rather take their chances on land than climb back into a boat. No one could blame them. And besides, it would stretch the provisions for the men in the boats.

By mid-December, after weeks at sea, the boats began to take on water, more whales menaced the men at night, and by January, the paltry rations began to take their toll. On Chase’s boat, one man went mad, stood up and demanded a dinner napkin and water, then fell into “most horrid and frightful convulsions” before perishing the next morning. “Humanity must shudder at the dreadful recital” of what came next, Chase wrote. The crew “separated limbs from his body, and cut all the flesh from the bones; after which, we opened the body, took out the heart, and then closed it again—sewed it up as decently as we could, and committed it to the sea.” They then roasted the man’s organs on a flat stone and ate them.

In avoiding cannibals, the men had become ones themselves.

Over the coming week, three more sailors died, and their bodies were cooked and eaten. One boat disappeared, and then Chase’s and Pollard’s boats lost sight of each other. The rations of human flesh did not last long, and the more the survivors ate, the hungrier they felt. On both boats the men became too weak to talk. The four men on Pollard’s boat reasoned that without more food, they would die. On February 6, 1821—nine weeks after the sinking of the Essex—it was proposed that the remaining men draw lots to determine who would be eaten next. The short end of the straw was drawn by Owen Coffin, the captain’s first cousin. And the man who drew the straw–Charles Ramsdell–was required to shoot him.

It was a horrific choice, but one the two men dispatched.

Thus, the survivors lived another day.

By February 18, after 89 days at sea, the last three men on Chase’s boat spotted a sail in the distance. After a frantic chase, they managed to catch the English ship Indian and were rescued.

Three hundred miles away, Pollard’s boat carried only its captain and Charles Ramsdell. They had only the bones of the last crewmen to perish, which they smashed on the bottom of the boat so that they could eat the marrow. Almost a week after Chase and his men had been rescued, a crewman aboard the American ship Dauphin spotted Pollard’s boat. Wretched and confused, Pollard and Ramsdell did not rejoice at their rescue, but simply turned to the bottom of their boat and stuffed bones into their pockets. Safely aboard the Dauphin, the two delirious men were seen “sucking the bones of their dead mess mates, which they were loath to part with.”

Years later, the third boat was discovered on Ducie Island; three skeletons were aboard. Miraculously, the three men who chose to stay on Henderson Island survived for nearly four months, mostly on shellfish and bird eggs, until an Australian ship rescued them.

The five Essex survivors were reunited in Valparaiso, where they recuperated before sailing back for Nantucket. Rumors of the ship’s ordeal soon spread like wildfire. Though the crew’s cannibalism was, for the most part, seen as acceptable given the dire circumstance, Owen Coffin’s mother never forgave Captain Pollard. Neither did Pollard, it seemed, forgive himself. Once a year, on the anniversary of the wreck of the Essex, he was said to have locked himself in his room and fasted in honor of his lost crewmen. Though he eventually returned to whaling, the wreck of his next ship, Two Brothers, upon a coral reef sealed his reputation as unlucky at sea.

He never sailed again, instead living out his remaining years on land, as Nantucket’s night watchman.