Mimir is one of the stranger figures of the Aesir pantheon. In his current form, the form we encounter him in as readers, the god is just a disembodied head. Despite this (or perhaps because of it) Mimir is a god associated with wisdom and the pursuit of knowledge.
He is mentioned many times across many stories and through many kennings, but his personal story is short and it seems that his role within the pantheon is more important than his former deeds.
Mimir’s main attestations are the Prose and Poetic Eddas, Heimskringla, and the poems Sigrdrifumal and Fjoolsvinnsmal. He is referenced mostly in association with other gods within their own myths.
Before he lost his body, Mímir was a respected and wise Aesir. He may be the brother of Bestla, making him Odin's uncle. This makes sense, as he was considered important enough to be traded to the Vanir as a hostage to secure peace in the war between the two tribes. Mimir and Hœnir (Odin’s brother in some stories) were traded for Njordr, Freyr and Freya.
The Vanir thought Hoenir was a fantastic trade – he was described as tall, handsome, and a capable warrior – and made him a chieftain. It soon became apparent, however, that he couldn’t make a decision without Mimir’s council. In retribution for this weakness, they cut off Mimir’s head and sent it back to the Aesir. Fair enough.
Not to miss a golden opportunity, Odin embalmed the head with a secret recipe of herbs and spices, and spent years carrying it around, gleaning all of the wisdom he could from it. Afterwards, he set the head to guard the well of wisdom which bears Mimir’s name – Mimisbrunnr.
The guardian of the well drinks from its waters, expanding his already substantial wisdom. Odin visits Mimir again and famously exchanges his eye for a drink from Mimisbrunnr, and it may be that the god Heimdallr traded one of his ears for a drink as well.
Disembodied heads as gods is a common theme throughout Norse, Celtic and Saxon myths – amongst others, though the similarities between these cultural cousins are striking. For instance, Bran the Blessed may be a version of Mimir (or vice versa) and his disembodied head is set to guard the island of Britain, offering wisdom to future chieftains and kings.
Other headless/disembodied head deities around the world include Chinnamasta, Ganesha, John the Baptist, Baphomet, Medusa, and Ketu. In fact, all throughout history, across many cultures, heads were revered as the seat of the soul, of wisdom, of vitality and power, and were variously chopped off, used as decorations, shrunk, preserved, displayed, eaten … the list goes on. Heads are culturally important, aside from being medically necessary for life, as symbols, both spiritual and political.
As an older god, the brother of Bestla and son of the Jotunn Bolborn, Mimir is closer in blood to the ancient Jotnar. In fact, this must have been a distinguishing feature for him at some point, as kennings exist for him relating to giant-kind, including “mischief-Mimir” (a kenning for giants.)
It seems that re-using jötunn bodyparts was something of a tradition amongst the gods. Óðin and his brothers created Midgard out of the body of the first giant, Ymir, and his head became the dome of the sky … while his brains became the clouds.
Signs and Symbols
Heads. Wells and fountains. Emblems of wisdom, learning, and knowledge – especially occult or secret knowledge! Advice, counseling, and teaching. Pickles if you’re desperate.