The idea that the dead walk the earth is both universal and ancient. From the widespread nature of the ethnographic manifestations and their appearance in historical texts, we can assume that beliefs in the walking dead - either corporeal or spiritual - was prehistoric, although that conclusion requires something of a leap.

The Eyrbyggia Saga describes some great ghosts as does the Grettissaga inn starka. Following is an excerpt from my Introduction to Folklore, which I recently e-published; the text provides some material on ghosts as well as an example of a story with a medieval expression (with a likely pre-conversion counterpart) of the story:

People tells stories about the dead appearing before the living perhaps in all cultures, but there are several forms they can assume. Some cultures emphasize animated corpses and that the dead can bodily rise from the grave and walk the earth. Others have traditions involving the dead appearing only as disembodied spirits. Most people think of the dead in human form. This is a requirement for animated corpses, but it is also a general assumption about spirits. There are, nevertheless, legends of souls and ghosts appearing as animals.

The attitude of the dead can be hostile or favorable to the living. The farther east one goes in Europe, the more likely that the dead will be hostile to the living. In general, walking corpses do little good, but the spirits of the dead, while sometimes benevolent, can also be dangerous. Legends about the dead should be considered along these lines. In modern North America, ghosts are generally spirits in human form, and in folk tradition they usually are good-willed toward the living. Films and literature contradict this by often depicting the dead as perilous for the sake of drama.

The Lenore Legend is one of the older and more widespread stories about the dead. It was so well known that Aarne and Thompson include it in their folktale index (Type 365), even though it is more often told as a legend, that is, to be believed. In the story, a young bride waits for the return of her betrothed who has gone off to war. Other soldiers come home, but not the man she loves. One night, he appears before her and asks her to leave with him. Delighted to see him, she climbs up behind him on his horse, and they ride quickly across the moonlit landscape. At one point, his horse jumps over a fence, and he pitches forward, revealing that the skin has been sheared off the back of his head, and his white skull shines bright in the moonlight. In other variants, his bride looks down at a stream they are crossing, and in the moonlight, she sees their reflection, revealing her companion to be a rotting corpse. Just as they reach his open grave, she jumps from the horse, saving herself. Her bridegroom returns to his grave, which supernaturally closes. The woman lives to tell her tale, but in many variants she dies soon after from the shock.

Gottfried August Bürger (1747-1794) made this story famous with his 1773 poem, “Lenore.” Within a decade after its publication, the German-language masterwork appeared in English translation, becoming an immediate sensation: it is credited with influencing Coleridge, Wordsworth, and other British poets of the newly-emerging Romantic era. In addition, the fame of Bürger’s poem and the association of the name “Lenore” with all things morbid may have influenced Edgar Allen Poe to write his own poem with this name and to feature the name in some of his other works.

The story appears to have considerable age as evidenced by the Old Norse story from The Poetic Edda, the “Second Lay of Helgi the Hunding-Slayer/Helgakviđa Hundingsbana II.” This describes how Helgi, a dead hero, returns from the grave on a horse to beckon his beloved, Sigrún, for one last night of conjugal bliss. The document suggests that originally the story may have played out differently: Sigrún willingly enters Helgi’s burial mound to lie with him. The poem subsequently relates that the heroine “lived but a short while longer, for grief and sorrow.” With this, the medieval text returns to the conclusion found in its more recent counterpart. This example suggests that for pre-Christian society, crossing the line into the supernatural – or at least in this case into the realm of the dead – for romance was heroic. Nineteenth-century expressions of the story generally assert that no living person would want to enter the grave, even when it is the last resting place of a lover. In a Christian context, the living must have no greater love than the one reserved for God, and to choose death runs against Christian teaching.