Norse Mythology: God of war. He was the only god brave enough to put his hand in the Fenris- wolf's mouth so the gods could bind it. The wolf bit off his right hand. There is much debate about his lefthandedness. In the norse culture the right hand was given for a pledge, which could be why the right hand was placed in the wolf's mouth. It has also been noted, however, that the offering of the right hand is to show that it is free of weapons. A left handed person was sometimes considered evil because he could use a weapon with his left hand even though he shook with his right hand. Tuesday is named for Tyr who was known as Tiw, or Tiu, by the Anglo-Saxons.

(Nicole Cherry, A list of Norse Beings, http://www.ugcs.caltech.edu/~cherryne)