An author that was not particularly prolific to my knowledge (at least I am not aware of many works by him). While perhaps most generally well know for being the brother of Marion Zimmer Bradley, he apparently carried considerable standing amongst the writing community.
He wrote several swords and sorcery fantasy novels that I thoroughly enjoy in his own setting that details the battle between good and evil in grand detail. If you want it, he has it elves, demons, sorcerers, swordsmen, heroes, scoundrels, grandeur, and passion.