Oberon and Titania
In later times the fairies or elves were said to be ruled by the king of the dwarfs, who, being an underground spirit, was considered a demon, and allowed to retain the magic power which the missionaries had wrested from the god Frey. In England and France the king of the fairies was known by the name of Oberon; he governed fairyland with his queen Titania, and the highest revels on earth were held on Midsummer night. It was then that the fairies all congregated around him and danced most merrily.
“Every elf and fairy sprite
Hop as light as bird from brier;
And this ditty after me
Sing, and dance it trippingly.”
Midsummer-Night’s Dream (Shakespeare).
These elves, like the brownies, Huldra folk, kobolds, etc., were also supposed to visit human dwellings, and it was said that they took mischievous pleasure in tangling and knotting horses’ manes and tails. These tangles were known as elf-locks, and whenever a farmer descried them he declared that his steeds had been elf-ridden during the night.