לילית) and her daughters the Lilu from Hebrew demonology. Lilitu was considered a demon and was often depicted as subsisting on the blood of babies, and estries, female shapeshifting, blood-drinking demons, were said to roam the night among the population, seeking victims. According to Sefer Hasidim, estries were creatures created in the twilight hours before God rested. An injured estrie could be healed by eating bread and salt given to her by her attacker. Greco-Roman mythology described the Empusae, the Lamia, the Mormo and the striges. Over time the first two terms became general words to describe witches and demons respectively. Empusa was the daughter of the goddess Hecate and was described as a demonic, bronze-footed creature. She feasted on blood by transforming into a young woman and seduced men as they slept before drinking their blood. The Lamia preyed on young children in their beds at night, sucking their blood, as did the gelloudes or Gello. Like the Lamia, the striges feasted on children, but also preyed on adults. They were described as having the bodies of crows or birds in general, and were later incorporated into Roman mythology as strix, a kind of nocturnal bird that fed on human flesh and blood. Medieval and later European folklore Many myths surrounding vampires originated during the medieval period. The 12th-century British historians and chroniclers Walter Map and William of Newburgh recorded accounts of revenants, though records in English legends of vampiric beings after this date are scant. The Old Norse draugr is another medieval example of an undead creature with similarities to vampires. Vampiric beings were rarely written about in Jewish literature; the 16th-century rabbi David ben Solomon ibn Abi Zimra (Radbaz) wrote of an uncharitable old woman whose body was unguarded and unburied for three days after she died and rose as a vampiric entity, killing hundreds of people. He linked this event to the lack of a shmirah (guarding) after death as the corpse could be a vessel for evil spirits. In 1645, the Greek librarian of the Vatican, Leo Allatius, produced the first methodological description of the Balkan beliefs in vampires (Greek: vrykolakas) in his work De Graecorum hodie quorundam opinationibus ("On certain modern opinions among the Greeks"). Vampires properly originating in folklore were widely reported from Eastern Europe in the late 17th and 18th centuries. These tales formed the basis of the vampire legend that later