On Zetacron, the nature goddess Gaia did not create the elves, but wished to claim them as Her own (it seemed fitting to her, somehow, that elves should be bound to Nature). Thus, she used her divine powers to create a bond between Herself and the elves.
A rumour of the knights of some powerful king that sleep until danger threatens the kingdom.
The truth is that they were rebels, trying to split the kingdom. Once captured they were put into an enchanted sleep, protected from age and harm, until their aims have been carried out by others in which case they will awaken.
There is a loophole in the spell in that trying to take one of their weapons will also awaken them.