Cyrus the Great makes a deal with blood-drinking demons in order to take the city of Babylon without battle. The demons comb the streets, killing any in their path, and the city falls to Cyrus after a single night. When Cyrus fails to hold up his end of the bargain, however, the demons seek their revenge, aiding the Massagetae empress a few years later in defeating him and his army. The empress, Tomyris, places Cyrus’s decapitated head in a vessel of fresh human blood as a gift for the female demons.

A rot fiend makes its way into the city of Athens, spreading pestilence and death in its wake. By the time the demon moves on, tens of thousands of people are dead from its plague, including the city’s leader.

A witch practicing in the Temple of Jupiter in Pompeii grows frustrated, unwittingly unleashing a burst of energy strong enough to be mistaken as an earthquake. The surrounding area suffers major damage. A similar power surge occurs seventeen years later, though the damage is far more cataclysmic.

Angered by the increased presence of man due to a local celebration, an elemental giant causes massive amounts of damage to the city of Antioch, first with an earthquake and then by sparking fires for days to follow. Most buildings are destroyed in these fires, though attempts are made to rebuild despite smaller tremors lasting for months after the initial shock. Two years later, many of those reconstructed buildings are destroyed again by another earthquake.

The Byzantines begin using Greek fire in naval battles to set not just enemy ships on fire, but the water as well. The compound is impressively destructive, and credited with many naval victories. The composition of this substance is deemed a mystery, though history forgetting about the existence of dragons is a key factor to that conclusion.

Magic users begin to vanish, with no evidence to explain the disappearances. This continues for years, with nearly two hundred magic-wielders going missing during this time.

A fast and violent storm spreads across the lands, crescendoing with a flash of green light. Most knowledge of magic is wiped from history.

Two children wander into the village of Woolpit. They appear normal, save for the green appearance of their skin. After they are taken into the village, their skin gradually loses its unusual pigment. Only the girl survives long enough to learn English. She reveals she and her brother had traveled from their subterranean land to explore this one. The existence of this strange world full of green people is dismissed as fantasy.

For nearly two hundred years, the coast of the North Sea was periodically ravaged by a giant sea serpent. By causing catastrophic floods, the leviathan is able to feast on entire populations as villagers are swept into the sea. During this period, the floods claim nearly half a million lives.

A powerful grimoire, hundreds of years old already, surfaces in Italy. Centuries later, when it is uncovered, it is called the Voynich manuscript, and deemed an indecipherable mystery. The real book finds its way back into the world in 1969, when a fake is swapped in its place and donated to Yale University.

One by one, the Norse settlements in Greenland - thriving for hundreds of years - mysteriously disappear. History will blame cooling temperatures of the Little Ice Age, but these weather changes are caused by the draugr. These undead creatures, rotting and horrible, descend upon the settlements, causing villagers to suffocate in their sleep, go mad, and even turn on each other. The unprecedented cold causes famine, which kills many as well. The settlements are abandoned in time, to escape these unreal horrors.

In Strasbourg, Alsace, a young woman is left scorned by her lover, who chose to marry another. The woman’s anger unintentionally triggers a phenomenon referred to as dancing mania. She only intended to harm the man who broke her heart, but it was his new wife that was first hit with this unfortunate affliction. Over the course of several days, hundreds of others are affected as well. Many die.

The coastal village of Autumn Grove is established in Massachusetts.

The restless spirits of Jamestown settlers, notably those who starved to death after turning to cannibalism in an attempt to survive, begin to terrorize residents of the town. The statehouse burns down during one of these paranormal events. The decision is made not to rebuild, and the capital of the colony is instead moved. Jamestown is abandoned.

The pirate ship Whydah Gally sinks off the coast near Cape Cod, during what appears to be a violent storm. The ship is ripped apart, with pieces of the hull, the bodies of the crew, and much of the cargo scattered across miles of coast. The sea monster that truly caused this destruction is never identified.

An Autumn Grove couple strolls through the forest, unknowingly encountering an insidious creature along the way. As the man steps onto a bridge, it appears to collapse. The woman flees in search of help, but when a party returns, the bridge is whole and her husband is nowhere to be found. The incident is attributed to hysteria. This is the first time such an encounter is officially recorded, though it is not truly the first, nor would it be the last.

Following the 1815 eruption of Mount Tambora, the Northern Hemisphere finds itself in a volcanic winter that causes significant temperature drops and food shortages. The nuckelavee, usually confined during the summer months, is able to freely roam the world. Two-headed and skinless, with black blood visibly flowing through its veins, this horror spends the frigid, icy months bringing pain and suffering to people already struggling to survive the unseasonable cold.

A kraken sinks five ships off the coast of August Grove in under three years. Two additional lighthouses are built along the town’s shoreline, to protect sailors from the unseen threat.

After crossing the Atlantic from New York, the merchant ship Mary Celeste comes upon another ship. Smoke suggests a fire aboard, and three crewmen take the ship’s lifeboat over to try to help. The men find the entire crew dead, though not from fire. Sensing something unnatural has occurred, they sail on quickly, not realizing the ghosts that had caused the ship’s crew to begin killing each other had followed the crewmen aboard. A day later, all aboard the Mary Celeste begin turning on one another. The captain’s wife is the last left alive after the slaughter, though the insidious spirit possesses her as well, leading her to throw all the bodies overboard before jumping into the sea to drown herself. The ship is found abandoned, with no evidence to explain what had happened aboard.

A forest guardian takes offense when it encounters a hunter in its woods. The man is never seen again. Over the next five years, five people total go missing, and the area of Vermont comes to be known as the Bennington Triangle. The fifth victim, a woman who was camping, is the only one to have her body recovered, namely because the deity finds her to be an unsatisfactory meal. Displeased after this, the guardian moves on, and the disappearances stop.

A local knitting circle moves their gatherings to Autumn Grove’s Circle Beach, after three tourists drown over the course of just one month. Though they never explain why, they begin warning people entering the beach at sunset against going near the water after dark. To this day, the knitters, now a group of grandmothers, continue with their knitting circle and their cryptic warnings. The sirens still find victims, but not nearly as many as before.

After exploring many forests along the east coast since leaving Vermont, the forest guardian settles in Autumn Grove. A hiker goes missing within weeks.

A demon residing in the magma chambers beneath Soufrière Hills awakens after centuries of slumber, causing a massive eruption unlike anything the island of Montserrat has experienced in modern history. Demanding a sacrifice of human flesh, the demon blankets the area in ash and volcanic matter and the eruptions continue, eventually rendering the area uninhabitable. The capital of Plymouth is abandoned as a ghost town.

A group of teens sneak out before Halloween to egg houses on a neighboring street. An entire carton is dedicated to a single home, as it is allegedly unoccupied and the children have no worries about getting caught. Unfortunately, a banshee had taken up residence within the abandoned old house, and, disturbed by their mischief, lashes out. The kids are found the next morning, incoherent and hysterical. It takes weeks of in-patient psychiatric care before any of them are released from the hospital.

Disinterested in the slaughter of unsuspecting seafarers, a mermaid takes up residence at Echo Beach, away from the areas often prowled by more bloodthirsty sirens. A local stumbles upon her one night, and, terrified by her appearance, throws a rock to strike her. She does not respond well to this. A few days later, his drowned body washes up on the beach. It isn’t the drowned body that surprises locals, but the beach it’s found on.

During February's full moon, the dog population of Autumn Grove seems to collectively lose their senses. The animals bark uncontrollably for much of the night. The same thing occurs during each full moon to follow that year.

The morning after a full moon, Sam Cavanaugh wakes up naked in a field, miles from home, with no memory of the night before.