Lord Dunsany and The King of Elfland’s Daughter, William Hope Hodgson and The House on the Borderland, E. R. Eddison and The Worm Ouroboros, Mervyn Peake and the Gormenghast trilogy — would that more modern-day writers would mine some of it for inspiration, instead of giving us nth-generation copies of LOTR as filtered through D&D, or yet another mutated descendant of Cthulhu.
Would also like to mention Hope Mirlees’ Lud-in-the-Mist, whilst we’re talking about pre-Tolkien fantasy. Absolutely worth everybody’s time to read.