The Vampyre by John Polidori

This book was originally attributed to Lord Byron, but it was actually written by his physician, John Polidori. It tells the story of a young aristocrat, Aubrey, who finds himself attracted by the mysterious Lord Ruthven. When he discovers that Ruthven is a brute committed to destroying women's reputations and lives, Aubrey tries to pull away, only to have the vampire Ruthven take his revenge on Aubrey's family. Sensationalist and lurid, this book is one of the earliest vampire stories.