Horror fiction is a genre of fiction in any medium intended to scare, unsettle and horrify the audience. Historically, the cause of the "horror" experience has often been the intrusion of a disturbing supernatural element into everyday human experience. Since the 1960s, any work of fiction with a morbid, gruesome, surreal, or exceptionally suspenseful or frightening theme has come to be called "horror". Horror fiction often overlaps science fiction or fantasy, all three categories of which are sometimes placed under the umbrella classification speculative fiction.
Lovecraft's guiding literary principle was what he termed "cosmicism" or "cosmic horror", the idea that life is incomprehensible to human minds and that the universe is fundamentally alien. Those who genuinely reason, like his protagonists, gamble with sanity. As early as the 1940s, Lovecraft had developed a cult following for his Cthulhu Mythos, a series of loosely interconnected fiction featuring a pantheon of human-nullifying entities, as well as the Necronomicon, a fictional grimoire of magical rites and forbidden lore. His works were deeply pessimistic and cynical, challenging the values of the Enlightenment, Romanticism, and Christian humanism. Lovecraft's protagonists usually achieve the mirror-opposite of traditional gnosis and mysticism by momentarily glimpsing the horror of ultimate reality and the abyss.
Although Lovecraft's readership was limited during his life, his reputation has grown over the decades, and he is now regarded as one of the most influential horror writers of the 20th century. According to Joyce Carol Oates, Lovecraft — as with Edgar Allan Poe in the 19th century — has exerted "an incalculable influence on succeeding generations of writers of horror fiction". Stephen King called Lovecraft "the twentieth century's greatest practitioner of the classic horror tale."
Vampires are mythological or folkloric beings who subsist by feeding on the life essence (generally in the form of blood) of living creatures, regardless of whether they are undead or a living person. Although vampiric entities have been recorded in many cultures and in spite of speculation by literary historian Brian Frost that the "belief in vampires and bloodsucking demons is as old as man himself", and may go back to "prehistoric times", the term vampire was not popularized until the early 18th century, after an influx of vampire superstition into Western Europe.
The success of John Polidori's 1819 The Vampyre established the charismatic and sophisticated vampire of fiction as it is arguably the most influential vampire work of the early 19th century inspiring such works as Varney the Vampire and eventually Dracula. However, it is Bram Stoker's 1897 novel Dracula that is remembered as the quintessential vampire novel and which provided the basis of modern vampire fiction. The success of this book spawned a distinctive vampire genre, still popular in the 21st century, with books, films, video games, and television shows. The vampire is such a dominant figure in the horror genre that literary historian Susan Sellers places the current vampire myth in the "comparative safety of nightmare fantasy".