Her, Bram Stoker, Ambrose Bierce, Edgar Allan Poe, Robert Louis Stevenson, Robert W. Chambers, Horace Walpole, Ann Radcliffe, Mathew Lewis, Sheridan Le Fanu, Nathaniel Hawthorne... that's just off the top of my head. Having said that. Lovecraft was king of horror before Stephen King in the 20th century (though nowhere near as popular as the guy from Maine during his lifetime) and deserving of the honor, IMO.