Until the Renaissance (14th century to 17th century) the main sources of children's literature in the Western world were the Bible and the Greek and Latin classics.
In England the earliest forms of oral literature, passed from generation to generation, were simple folktales, usually of Celtic and Anglo-Saxon origin.
Blake's ideas on the innocence of children and their corruption by adult standards of belief and behavior are also derived from a blend of German mysticism, English Protestantism, and the political ideas of the French Revolution.