While the folklore that fantasy drew on for its magic and monsters was not exclusively medieval, elves, dragons, and unicorns, among many other creatures, were drawn from medieval folklore and romance. Earlier writers in the genre, such as George MacDonald in "The Princess and the Goblin" (1872), William Morris in "The Well at the World's End" (1896) and Lord Dunsany in "The King of Elfland's Daughter" (1924), set their tales in fantasy worlds clearly derived from medieval sources, though often filtered through later views. In the first half of the twentieth century pulp fiction writers like Robert E. Howard and Clark Ashton Smith helped popularise the sword and sorcery branch of fantasy, which often utilised prehistoric and non-European settings beside elements of the medieval. In contrast, authors such as E. R. Eddison and particularly J.R.R. Tolkien, set the type for high fantasy, normally based in a "pseudo-medieval" setting, mixed with elements of medieval folklore. Other fantasy writers have emulated him, and films, role-playing and computer games also took up this tradition. Modern fantasy writers have taken elements of the medieval from these works to produce some of the most commercially successful works of fiction of recent years, sometimes pointing to the absurdities of the genre, as in Terry Pratchett's "Discworld" novels, or mixing it with the modern world as in J. K. Rowling's "Harry Potter" books.