One tenth-century Englishman knew exactly how to deal with sea monsters.
Within (that's his name) is described as a fisherman with a reputation for handling river and sea expeditions with equal skill. One trip, however, proved far different than the others. He had set out into a calm sea, thrown his anchor, cast his nets. He had a full basket of bread and a jug of fresh water to sustain him and "exulted" in the day.
Until his saw the creature, of course.
It was Scylla and Charybdis combined, with a toothy maw "that could tumble entire cities to the underworld." But Within didn't panic--he knew how to handle this. He pulled up his anchor, brought in his nets, and headed for shore. But alas for Within, his typical strategy failed him today. The monster pursued him! Within started to panic, which was all the opening the beast needed.
The creature opened its serpentine mouth and swallowed man and boat alike.
Clearly, it was time for Plan B.
Within found himself, well, within the creature, resting on its internal organs. In the pitch blackness, he struck flint to steel, turning his oars to torches. He assessed his supplies: a boat made of wood and a sword. That should do. He chopped up the sides of his raft, lit them on fire, threw them against the insides of the creature's stomach. Oh, how the beast roared! Fire spewed painfully out its mouth. Within wasn't finished. As his little prison burned and smoldered, he sliced and stabbed at its walls with his sword.
His purpose was twofold. First, he had to kill the creature. Second, he needed dinner. Prey had become predator.
For four scary nights Within sat in his dying cave, roasting organs on a spit. On the fifth day, the beast washed up onto the shore--and by perfect coincidence, right near his home port of Rochester.
The townspeople rushed to the beach. They, too, knew exactly how to deal with a whale on shore. Meat, bones, oil! A windfall. They grabbed their axes, began to dismantle. And then they stopped short. A voice emerged from--inside the whale? A voice speaking--English? The devil's work!
The local priest performed an exorcism. But no exorcism was needed--just, as Within told them, for them to keep slicing, but please do so carefully.
He was saved.
~~
Of course De quodam piscatore quem ballena absorbuit, a poem by a French monk named Letaldus, is an invention. Despite its talltale or folktale-esque nature, its sophisticated Latin meter and abundant Greco-Roman references (Scylla and Charybdis is in the original!) point to the advanced education of poem's author and intended audience.
But while Letaldus' familiarity with classical literature may have been particularly advanced, De quodam piscatore illustrates one of the thorniest problems when talking about realities of sea monsters in the Middle Ages. The sea-beast ne plus ultra is the whale that swallowed Jonah. And going back to foundational Church Fathers Jerome and Augustine, Christian theologians had invested a lot of angst and effort into asserting the validity of that story against their opponents. Medieval methods of biblical interpretation heightened the stakes. Jonah prefigured Christ; the whale hell. The allegorical Hell-mouth swallowed Jonah and spit him back out, God's triumph over hell. Educated medieval writers needed to believe in the monsters of the sea.
What does seem clear, though, is that medieval people--landbound, occasional travelers, and sailors alike--regarded the sea with a mixture of respect and terror. In religious literature and travel narratives alike, storms and enormous monsters in particular served to embody the dangers of the depths.
One way to deal with monsters of the sea, of course, was to catch them! In the north, whaling on land and sea was an important part of economy, even regulated by law codes. In the late Middle Ages, Basque and Bristol fishermen competed fiercely for dominance of whale fishing between Iberia and England. At sea, "piercing" and "shooting" weapons would be used to kill the fish, but the real prize--and the legal complexities--arose when whales were beached.
But whaling was serious business. Aelfric's Colloquy has its fisher say, "I prefer to catch a fish I can kill rather than a fish that can sink or kill not only me but my companions with a single blow." This illustrates an important point about sea-monsters in medieval descriptions: they are enormous and powerful. The Voyage of St. Brendan, a folksy hagiography that became a runaway bestseller across medieval Europe, has whales the size of islands. Felix Fabri, on pilgrimage to Jerusalem in the late Middle Ages, described the hippopotamus of the Nile as "the worst beast." And Martin Luther described the beaching of a gigantic whale (seventy-five feet long and thirty feet wide!) at Haarlem as a sign of God's impending wrath, the end of the world itself.
Sea monsters, in other words, were forces of nature and supernature. As such, medieval sailors tried similar means to combat them. In the early Middle Ages, consecrated Eucharist hosts were carried aboard ships for protection from the dangers of the sea, storms and monsters. In sixteenth-century Spain, sailors carried saints' relics to similar purpose.
Medieval ships certainly had ways of dealing with hostile forces, that is to say, pirates. In 1515, Bernardo di Marconi and Marcantonio Dandolo petitioned Venice to loan their galley two pieces of stone-throwing artillery for their charter to carry pilgrims to Jerusalem. This was apparently a good decision, because the next year Marconi bought the cannons outright.
The last way that we can see medieval people grappling with the great unknown of the sea and its creatures is the effort to understand it. I want to highlight that we are often talking about people who grew up near or on ports, rivers, seas; some of them had a lifetime of experience. It is not a question of "greater" understanding but rather shifting types.
Looking at medieval maps and descriptions, there is a clear tendency to portray sea-creatures as land equivalents. The sea lion is actually a lion; the sea chicken is...no, really. The pilgrim known as the Anonymous Parisian describes the monster he saw as having "the wings of a bat." Interestingly, the impulse to describe the Unknown in terms of the known and thus comfortable, if dangerous, will be repeated in early writings from colonial America.
But over time, the depiction of sea monsters on maps actually shifts. The serpentine Nessie is a classic, of course, but by the 16th and 17th century there is much greater attention to whales that look like whales, walruses that look like walruses. Alain Corbin has demonstrated that this move towards observation was hardly (western) humanity's conquest of the sea. As its understanding shifted from the supernatural to the natural, so too did its dangers. Sixteenth-century Luther saw sea creatures on land as the world upside down, the hallmark of the end days; eighteenth-century travelers were horrified by their seasickness more often and more violently than before or since.
Hic sunt leones is the classic cartographical reference to the world beyond the world, the great unknown: "Here there are lions." Medieval people who confronted the sea couldn't settle for that. On one hand, it was a resource and a road. On the other, "here there are monsters."
Further Reading:
Maybe a more appropriate question: what was the view at the time of the existence of these sort of sea monsters? Were they dismissed by most as fictional stories? Did scientists attempt to prove their existence, or were they already considered fact or fiction in the scientific community? Were sailors and/or explorers fearful of encountering a sea monster on their travels?