Tyr is a Norse god associated with law, binding agreements, courage, and battle. The surviving Old Norse sources give him fewer stories than Odin or Thor, yet the binding of the wolf Fenrir makes his character clear: he accepts a personal loss so that a dangerous pledge can be completed.
The hand pledged to Fenrir
The gods ask Fenrir to test the magical bond Gleipnir. Suspecting a trap, the wolf agrees only if one god places a hand in his mouth as a guarantee. Tyr alone accepts. When Fenrir cannot escape and the gods refuse to release him, the wolf bites off Tyr’s hand.
Law and warfare
The name Tyr is related to an older Germanic word for a god, and Roman writers equated a Germanic deity with Mars when naming the weekday that became Tuesday in English. This comparison does not make Tyr a copy of Mars. Norse poems use him in the language of battle and legal honor.
What the sources do not show
Calling Tyr simply the chief Norse god of war gives him a position the medieval texts do not consistently assign. Snorri says he is brave and invoked by warriors, while poetic evidence links his name with victory and assembly. His family and wider cult history remain less certain than modern charts suggest.