Magic of Metallurgy
The drawing of a sword from a stone is a metaphor for the science of metallurgy, itself a drawing-out of iron from ore or stone. (The metallurgical cult aspect or image of the Sword in the Stone is made even more plain in several versions of Arthur’s tale where the sword is actually in an anvil sitting on a stone.) In earlier times the secrets of metallurgy were the equivalent of today’s atomic secrets. A nation that acquired the secret of smelting iron and forging metal was able to obliterate its less technologically advanced neighbour. And as the science of metallurgy advanced throughout the Iron Age, a new innovation (forging superior steel, or making armour or chain mail) would result in a chain reaction of revolutions, mass migrations, murderous conquests and collapsing empires.
The secrets of metallurgy were controlled by alchemists and smiths. Protective of their craft, these men often lived in closed societies with little contact with the rest of the culture and they were frequently hidden deep in mountain or forest refuges where enemies could not find them. Surrounded by mystery and isolated from the rest of the population, an aura grew around these metallurgical specialists and they were perceived by to have a special kind of power over even the mightiest nobles of the kingdom. Consequently, these outcast alchemists and smiths acquired an ambivalent reputation. They were both feared and respected by the general population and over time they were also mythologized, emerging as the supernatural wizards and dwarfs of Norse, German and Celtic myths and legends.
— David Day, The Search For King Arthur, p. 32