Mimir is a primal god who is renowned for his knowledge and wisdom. Mimir is the giant brother of Odin’s Jotun mother Bestla and he is the guardian of the Well of Mimir, in which all wisdom lies. Odin sacraficed one of his eyes in exchange for drinking from Mimir’s magical well, to acquire Mimir’s omniscient wisdom and knowledge for himself.
Mimir was sent to the Vanir as a hostage with Hoenir, but when Hoenir’s slowness of speech was discovered, the Vanir became angry. Unwilling to harm Odin’s brother, they lopped off Mimir’s head instead and sent it back to the Aesir. Odin preserved it with herbs and spells, and gains much wisdom from consulting with the head. In this manner Mímir is known to have taught Odin great and mystical wisdoms and magical formulae, furthering his own immense store of knowledge by drinking daily from the timeless spring which still remains in his charge.