‘Ulf and Odin,
and High Tyr,
is help for Bur,
against these pain
and Dwarf sword,
Bur.’ (MacLeod and Mees 2006, p. 24)
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The runic inscription appears to invoke a triple force of protectors to fight a Dwarf. These are Ulf or wolf, which may represent Fenrir, then Odin the chief Norse god, followed by High-Tyr who is probably the warrior god Tyr. These will aid Bur, who is most likely Borr/Burri, Odin’s father (it is also possible that Ulf/Odin/High-Tyr, represent a divine trinity of the same god, Odin).
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In Norse mythology Odin was thought to have healing powers, while dwarves were often associated with disease. In light of this the pendant may have been used as a talisman to protect against illness. The use of a human skull probably imbued the amulet with extra potency and this is not unlike the role played by corporeal relics in the Christian tradition.
References
MaCleod, M. & Mees B. (2006) Runic Amulets and Magic Objects, Boydell Press, Suffolk