Upon setting sail from the Spanish port of Seville in 1519, at the head of his Armada of the Moluccas, Ferdinand Magellan was unsure of just what to expect.

He had a hunch that sailing west would take him to the Spice Islands. He was also confident he could find the fabled maritime passage through the continents claimed by the two competing seafaring superpowers of the time.

A few decades earlier, under pressure from the Catholic rulers of Spain, the Pope had drawn an imaginary line on the map from pole to pole and split the world in two. Spain was granted exclusive rights to territories west of the divide, with Portugal expected to keep to the east. The deal was sealed in the small Spanish town of Tordesillas in 1494.

Dismissed by King Manuel of Portugal, to whom he first pitched the idea of an expedition, a humiliated Magellan crossed the border into Spain, where he got the attention of Charles I, then in his teens.

When Magellan authoritatively declared that the Spice Islands lay in the Spanish hemisphere and that he knew how to get there, the monarch was sold and granted the Portuguese navigator a full-fledged armada.

If his fleet could make it to the Indies, he would know how to return by sailing around Africa, using the route established years before by Vasco Da Gama. He could go down in history as the first man to circumnavigate the globe.

Magellan had a different goal in mind, though. He wanted to establish a reliable western route to the spices that grew in the East. Used as seasonings, food preservatives, and aphrodisiacs, these exotic commodities were worth many times their weight in gold. With as little as a sack of cloves, a sailor could buy a house, settle down on a good pension, and never leave port again.

On Sept. 20, 1519, the Armada of the Moluccas headed into the unknown. Magellan gathered the best technological and human resources available, leaving port with a flotilla of five ships loaded with provisions, hoping for the best in an uncertain voyage.

Under his command sailed a contingent of 260 men seduced by the promise of fortune and glory, their only chance to escape a miserable existence. The captain general knew he would be up against more than just the ferocity of the southern seas. He had dared to question pseudo-religious believers convinced that Magellan, in spite of his conviction, was attempting the impossible.

Sailing southwest, the armada soon made a pleasant landfall in the tropics. As they proceeded south, any waterway leading inland was explored in search of the canal.

As the weather worsened and provisions dwindled, the Spaniards grew sour. The crew resented having a Portuguese at the helm. Facing the prospect of a long winter, their impatience started to mount. That pent-up anger eventually escalated into full-blown mutiny, when they reached what is now Puerto San Julián, in modern-day Argentina.

With the help of a few loyal whistleblowers, Magellan was able to anticipate and crush the revolt. He did so with unspeakable cruelty. Mutineers were marooned, eviscerated alive or dismembered, their heads and limbs scattered through the five ships as a warning. Sour at the captain’s brutality, the crew of the San Antonio defected back to Spain, carrying with it most of the provisions. And during a reconnaissance journey, the Santiago ran aground.

On Nov. 1, Magellan started exploring a promising westward navigable seaway. Twenty-seven freezing days later, the three remaining ships emerged into the quiet waters of what he called Mar Pacifico (the Pacific Ocean). The legendary strait connecting east and west had been found and crossed.

The ordeal was just starting. It would take them 98 days to see dry land again, and by the time they did, scurvy and famine had claimed the lives of dozens of seamen.

After replenishments and repairs in modern-day Guam, the fleet advanced into what would later be the Philippines. To everyone’s surprise, Magellan’s slave Enrique, acquired in a journey to Malacca eight years earlier and brought along as an interpreter, could easily communicate with the rulers and natives in the various islands.

With Enrique’s linguistic support and the imposing thunder of cannons, Magellan had no trouble claiming a few islands for Spain. But when he tried to convert chieftain Lapu Lapu to Christianity by force, his fate was sealed on the island of Mactan. Shallow waters kept the ships away and cannon shots out of range. Overconfident and severely outnumbered, Magellan was brutally killed. Another eight Europeans perished that same day.

His master dead, Enrique was now free. He was also home. If the slave was actually from the Cebu region — as his command of the local language seemed to indicate — the first man to circumnavigate the world was actually an interpreter!

With Magellan gone, Sebastián Elcano, one of the mutineers, and other, less experienced pilots were reassigned as captains and tasked with finding their way back home through a complicated maze of islands. More than sail, they would need to talk their way through waters dominated by the Portuguese and immersed in languages totally unfamiliar to them. Not surprisingly, the new crew refused to release the interpreter.

Enrique was not having it. Disgruntled, he turned to Rajah Humabon, the ruler of Cebu, and plotted a conspiracy. He convinced the Rajah that disguised under the Europeans’ amicable attitude was an imperialistic plan to loot their land, depose the local ruler, and eventually claim their riches for Spain. He should lure them ashore, entrap them, and eliminate their threat. They had a plan.

Back on the ship, Enrique shared the news that the Rajah wanted to offer a farewell banquet to his new European friends that evening. There would be plenty of food, women, booze, and fun.

About 30 Europeans attended, indulged, and drank themselves silly. They did not see it coming. Closing the soirée at the Rajah’s command, archers emerged from the bushes in huge numbers and killed all of their guests but one: Enrique.

Shorthanded and fearing for their lives, the Spaniards burned one of their vessels, and resorted to raiding passing ships. Having also lost the Trinidad, the small surviving crew gathered on the Victoria and placed all their bets on their new pilot, Elcano, and their new interpreter: Antonio Pigafetta.

A Venetian scholar and explorer, Antonio Pigafetta had joined the expedition in search of adventure and probably paid a hefty sum for the privilege. From day one, he kept a detailed journal of the expedition’s trials and tribulations. He also compiled the first phrasebook in history with the help of Enrique.

Filled with drawings, Pigafetta’s journal provides a rich guide to the features and customs of the lands and peoples encountered during the voyage. This historic record is the only reason we can tell the story.

Finally, on Sept. 10, 1522, a battered ship docked at the port of Seville, manned by a skeleton crew of just 18 sailors. They were severely malnourished. Their teeth had fallen out, and the skin appeared to be melting off their bones. Most could hardly walk. Despite the hardships, the Victoria and what was left of its crew had made it back. And what little cargo it held was enough to turn a profit.

Lighting a candle works a lot better than cursing the darkness. Our fears, the ghosts of our time, must be challenged, one by one.

The intrepid Portuguese navigator, in the service of the Spanish king, did more than just find a western route to the East Indies. He had to face countless medieval superstitions.

Legends spoke of sailors swallowed up by boiling waters south of the Equator and of ships torn apart by magnetic isles that could pull the nails out from the hull. Magellan had to confront enemies that were far from imaginary.

Other than scurvy, whose cause would remain a mystery for another three centuries, all the adversaries he faced were known and very powerful — the violent seas, the raging storms, the mutinous sailors, the distance, the famine.

The captain general never sailed into boiling waters or magnetic rocks. He did not succumb in the jaws of a mythic serpent. Rather, he was the victim of his own poor judgment during an ill-considered and unnecessary show of force.

Ultimately, the Armada of the Moluccas paid a high price for challenging established myths and traditions. It sunk four ships and killed 200 seamen. It was, by most objective standards, an unqualified failure. But none of that stopped it from changing the world forever.

Despite his early death, Magellan earned his place in history. He had galaxies and space programs named after him. Sebastián Elcano, the pilot who steered the Victoria back home, was also celebrated in Spain with a coat of arms and his face on currency bills and stamps.

Yet to be fair, their glory would have to be shared with at least another two crew members. First, Pigafetta, without whom most of the story would have perished along with the ships. And finally, Enrique, the expedition’s interpreter, who made communication possible and who arguably went full circle earlier than anyone else.

Coming from opposite ends of the social spectrum, the learned nobleman and the humble slave accidentally brought on board weapons many times more persuasive than the sword to change history: their pen and their voice.