I know it sounds freaky but when living in Eastern Europe I heard a detailed documentary on the radio about vampires according to the Hapsburg (former royal family of Central Europe, centered in Prague and Vienna) archives and documented the possible reality of vampires. I doubt they were real but the panic was. Below are some facts (check out link to Dom Augustin Calmet and Montague Summers):
The Vampire in the Czech Republic and Slovakia: The Czech and Slovakian vampire-called a up'r, and to a lesser extent, nelapsi, in both Czech and Slovak-was a variety of the Slavic vampire. The upir was believed to have two hearts and hence two souls. The presence of the second soul would be indicated by a corpse's flexibility, open eyes, two curls in the hair, and a ruddy complexion. Among the earliest anecdotes concerning Czech vampires were two fourteenth-century stories recounted by E. P. Evans in his volume on the Criminal Prosecution and Capital Punishment of Animals (1906), as mentioned in Dudley Wright's survey. The first concerned a revenant that terrorized the town of Cadan. The people he attacked seemed destined to become a vampire like him. They retaliated, attacking his corpse and driving a stake through it. That remedy proving ineffective, they finally burned him. In 1345, in Lewin, a woman believed to be a witch died. She returned in various beastly forms and attacked villagers. When uncovered in her grave it was reported that she had swallowed her face cloth; when the cloth was pulled out of the grave, it was stained with blood. She also was staked, which again proved ineffective. She used the stake as a weapon while walking around town. She was finally destroyed by fire. Writing in 1863, Henry More recorded events that occurred in the late 1500s to Johannes Cuntius (or Kunz), a merchant who troubled his family and neighbors following his violent death. Cuntius lived in the town of Pentsch (present-day Horni Benesov). His son lived in Jagerdorf (present-day Krnov) in a part of Moravia dominated by Lutheran Protestants.
Dom Augustin Calmet included reports of vampires from Bohemia and Moravia in his famous 1746 treatise. He noted that in 1706 a treatise on vampires, Magia Posthuma by Charles Ferdinand de Schertz, was published in Olmutz (Moravia). Magia Posthuma related a number of incidents of vampires who made their first appearance as troublesome spirits that would attack their former neighbors and the village livestock. Some of the reports were of classic nightmare attacks accompanied with pain, a feeling of being suffocated, and squeezing around the neck area. Those so attacked would grow pale and fatigued. Other stories centered on poltergeist effects featuring objects being thrown around the house and possessions of the dead person mysteriously moved. One of the earliest and more spectacular cases concern a man of the Bohemian village of Blow (Blau) in the fourteenth century. As a vampire he called upon his neighbors, and whomever he visited died within eight days. The villagers finally dug up the man's body and drove a stake through it. The man, however, laughed at the people and thanked the people for giving him a stick to fend off the dogs. That night he took the stick out of his body and began again to appear to people. After several more deaths occurred, his body was burned. Only then did the visitations end.
Schertz, a lawyer, was most concerned with the activity of villagers who would take the law into their hands and mutilate and burn bodies. He argued that in cases of severe disturbances, a legal process should be followed before any bodies were desecrated. Included in the process was the examination of the body of any suspected vampire by physicians and theologians. Destruction of the vampire, by burning, should be carried out as an official act by the public executioner.
Montague Summers was most impressed by the evidence of vampirism detailed by the Count de Cadreras, who early in the 1720s was commissioned by the Austrian emperor to look into events at Haidam, a town near the Hungarian border. The count investigated a number of cases of people who had been dead for many years (in one case 30 and another 16 years), and who had reportedly returned to attack their relatives. Upon exhumation each still showed the classic signs of delayed decomposition, including the flow of "fresh" blood when cut. With the Count's consent, each was beheaded (or nails driven into the skull) and then burned. The extensive papers reporting these incidents to the emperor survived, as well as a lengthy narrative given by the count to an official at the University of Fribourg.
It is unlikely that the town of "Haidam" will ever be identified. No place by that name has been recorded. It has been suggested most convincingly that the term derived from the word "haidamak," a Ukrainian term meaning "outlaw" or "freebooter." Haidamak, derived from the Slavic "heyduck" referred to a class of dispossessed who had organized themselves into loose itinerant bands to live off the land. Eventually the Austrian Hapsburg rulers employed them as guardians along their most distant frontiers. This Haidam probably referred to the land of a haidamak rather than a specific town by that name.