H.P. Lovecraft (1880-1937) is a famous American author of horror, fantasy, and science fiction. Horror author Stephen King has called Lovecraft "The Twentieth Century's greatest practitioner of the classic horror tale," but this is misleading, because H.P. Lovecraft's tales were anything but classic. He is the originator of the concept of "cosmic horror" — the idea that the universe is incomprehensible to human minds and is fundamentally alien. Understand it well enough, and you're apt to go insane, like many of the protagonists in his stories. H.P. Lovecraft's deeply pessimistic and cynical worldview comes out in most of his writings.
H.P. Lovecraft had limited readership during his life, and died a poor man. But in the decades after his death, his work became much more popular, and today he is considered one of, if not the most influential horror writer of the 20th century. His works, including over a hundred short stories, have influenced countless books, movies, novels, music, comic books, and cartoons. He is most known for his Cthulhu Mythos, a series of loosely connected stories with commonalities in mythology — ancient evil gods and beings that threatened human beings in certain circumstances, like the grounds of a pitch-dark abandoned church in the middle of a storm. Another common feature in many of his stories are references to the Necronomicon, an ancient book filled with rites and incantations for summoning demons.
There are several common themes throughout H.P. Lovecraft's work that made it unique and memorable. Many of these features were later frequently copied in horror stories of every stripe, often by authors who are not even aware of their originator. These concepts are forbidden knowledge, non-human influences on humanity, inherited guilt, civilization under threat, and the risks of a scientific era. Lovecraft lived at a time when scientific and technological knowledge was expanding rapidly, and it was palpable how little humans knew. He used this to his advantage in his stories, where scientific investigations sometimes unveiled much more than his protagonists ever could have imagined.
Some of Lovecraft's most popular stories were Dagon, A Color Out of Space, The Shadow Out of Time, and At the Mountains of Madness.