Montague Summers (1880-1948) did a fantastic job researching the folklore and beliefs about vampires in many civilizations reading many books in different languages, including Greek, Latin, German, Italian (dialets), French, and English, to create one of the best works about vampires ever written and published. The author, a member of the Roman Catholic clergy, wrote numerous books about witches, vampires, werewolves, and other related subjects too. The Vampire, his Kith and Kin: The History of Vampirism is definitively a great book.