Mímir (Old Norse "The rememberer, the wise one") or Mim is a wisdom deity in Norse mythology. He is closely associated with a magical well of knowledge that bears his name, the Mímisbrunnr. At the conclusion of the Æsir-Vanir War he was sent to the Vanir along with the god Hœnir as part of a peaceful hostage exchange. Fearing trickery from the Aesir because of Hœnir's foolishness, the Vanir beheaded Mímir and returned his head to Asgard. In order to keep Mímir's wisdom, Odin preserved his head with magic so it could continue to provide knowledge and counsel as his advisor.