The Servants were creations of the Gods. It is said that their original purpose was to serve their masters in the Sky Realm. They were sent down to Dünya during the first age to help teach civilisations about harmony and Djinn magic.
They disappeared during the end of the first age for unknown reasons. Many believe that they are just myths.
From the text, 'Genesis of Dünya':
They soon found a way to harness this magic, at first capturing the essence in lamps. From this, they created the first piece of life. An automaton was made, and Djinn magic was wrought into its very being.
The named this automaton 'The Servant', and in its image, many were made to serve the academics of the Sky Realm.