Ghosts reported in medieval Europe tended to fall into two categories: the souls of the dead, or demons. The souls of the dead returned for a specific purpose. Demonic ghosts existed only to torment or tempt the living. The living could tell them apart by demanding their purpose in the name of Jesus Christ. The soul of a dead person divulged their mission, while a demonic ghost was banished at the sound of the Holy Name.^[48]

Most ghosts were souls assigned to Purgatory, condemned for a specific period to atone for their transgressions in life. Their penance was generally related to their sin. For example, the ghost of a man who had been abusive to his servants was condemned to tear off and swallow bits of his own tongue; the ghost of another man, who had neglected to leave his cloak to the poor, was condemned to wear the cloak, now "heavy as a church tower". These ghosts appeared to the living to ask for prayers to end their suffering. Other dead souls returned to urge the living to confess their sins before their own deaths.^[49]

Medieval European ghosts were more substantial than ghosts described in the Victorian age, and there are accounts of ghosts being wrestled with and physically restrained until a priest could arrive to hear its confession. Some were less solid, and could move through walls. Often they were described as paler and sadder versions of the person they had been while alive, and dressed in tattered gray rags. The vast majority of reported sightings were male.^[50]

There were some reported cases of ghostly armies, fighting battles at night in the forest, or in the remains of an Iron Age hillfort, as at Wandlebury, near Cambridge, England. Living knights were sometimes challenged to single combat by phantom knights, which vanished when defeated.^[51]

From the medieval period an apparition of a ghost is recorded from 1211, at the time of the Albigensian Crusade.^[52] Gervase of Tilbury, Marshal of Arles, wrote that the image of Guilhem, a boy recently murdered in the forest, appeared in his cousin's home in Beaucaire, near Avignon. This series of "visits" lasted all of the summer. Through his cousin, who spoke for him, the boy allegedly held conversations with anyone who wished, until the local priest requested to speak to the boy directly, leading to an extended disquisition on theology. The boy narrated the trauma of death and the unhappiness of his fellow souls in Purgatory, and reported that God was most pleased with the ongoing Crusade against the Cathar heretics, launched three years earlier. The time of the Albigensian Crusade in southern France was marked by intense and prolonged warfare, this constant bloodshed and dislocation of populations being the context for these reported visits by the murdered boy.