I've cited this in other threads, but the
Fafhrd and the Gray Mouser article starts with a history of swords & sorcery literature:
Sword and sorcery may not be the most critically acclaimed mode within the fantasy genre, but it's one of the most enduring and has proven perennially popular. The first sword and sorcery story was probably Dunsany's novella "The Fortress Unvanquishable, Save for Sacnoth" (1907), which brought together all the basic elements: an evil wizard, a brave young hero, a magic sword, and a host of obstacles preventing the hero from getting at the wizard with the sword. Sword and sorcery was a mainstay of the fantasy pulp magazines, best exemplified in the work of Robert E. Howard, whose Conan series (1932-36) pretty much set the standard for decades to follow. Howard may have been a hack, but he was an honest hack, able to vividly convey his own wild-eyed enthusiasm for violence as a solution to virtually any problem. Conan himself is a paean to the virtues of the Noble Savage who grows in character throughout the series, culminating in the novel Hour of the Dragon (also known as Conan the Conqueror) where a middle-aged Conan has acquired a sense of responsibility and fights to defend the subjects of his usurped kingdom.
Howard had many imitators, most of whom aped his style and lacked both his imagination and his sincerity, like modern-day musicians engineering pops and crackles into their songs to make them sound more like bygone artists they admire. One follower who avoided this trap was Michael Moorcock, who in the early 1960s attempted to re-invent the genre by inverting its conventions with Stormbringer (1963), the first (and best) of the Elric of Melniboné series. Instead of an uncivilized barbarian, Moorcock gives us an overcivilized decadent; instead of rising from adventurer to king, Elric declines from emperor to peopleless wanderer; instead of the straightforward Conan's loyalty and occasional gallantry, the subtle Elric betrays and brings about the death of every friend, subject, relative, or subordinate who puts their trust in him. In fact, Elric is just the sort of treacherous wizard whom Conan specializes in lopping the heads off of. Unfortunately, instead of stopping after the impressive feat of writing the epic tale of Elric's death, Moorcock proceeded to churn out a flood of prequels, all essentially retellings of the same story, diluting the impact of the original with every regurgitation.