Sif by John Charles Dollman, 1909. Sif is Thor’s wife, and most modern knowledge of Sif is derived from her association with Thor as few direct mentions of her have survived. Scholars believe her to be a goddess of fertility (sexual and agricultural), marriage, kinship, and peace. She’s the mother of the goddess Thrúd and the god Ull. Several of her mentions in the mythological record involve Loki. Her most noted attribute is her long, straight, golden hair, perhaps intended to represent golden wheat.