Odin (Old Norse: Óðinn) is the main god in Norse mythology. Described as an immensely wise, one-eyed old man, Odin has by far the most varied characteristics of any of the gods and is not only the deity to call upon when war was being prepared but is also the god of poetry, of the dead, of runes, and of magic.
He also exists in Germanic mythology as Woden (in Old English), Wodan (in Old Franconian), and Wutan or Wuotan (in Old High German). The modern English weekday name Wednesday traces its origins to "day of Woden", wōdnesdæg in Old English, and is still seen in the Dutch name woensdag.
Part of the Æsir family of the gods, he helped create the world, resides in Asgard (the stronghold and home of the gods), and gathers slain warriors around him in Valhalla ('hall of the slain'), but is eventually crunched to death by the wolf Fenrir in the Ragnarök, the 'final destiny of the gods' in which the world is destroyed.
Odin is an old, original character in Norse mythology although, as Jens Peter Schjødt points out, many scholars think that his elevated position at the top of the godly hierarchy may be a later addition (219). Odin's role of 'Allfather' or father of the gods is more of a literary theme from later sources - seemingly influenced by Christian names for God - than an actual reflection of his status in Viking Age societies. Skaldic poetry (Viking Age, pre-Christian poetry mainly heard at courts by kings and their retinues), for instance, names Baldr, Thor, and Vali as Odin's sons, whereas later on the 13th-century CE Icelandic author Snorri Sturluson also adds Heimdall, Týr, Bragi, Vidarr, and Hodr to the list. Incidentally, despite him being married to Frigg a lot of these sons are from different mothers and Odin appears in many stories as a womaniser, even boasting of his affairs, reminiscent of (and perhaps inspired by?) Zeus from Greek mythology.