Sif is a golden-haired goddess associated with earth. Sif is attested in the Poetic Edda, compiled in the 13th century from earlier traditional sources, and the Prose Edda, written in the 13th century by Snorri Sturluson, and in the poetry of skalds. In both the Poetic Edda and the Prose Edda, she is known for her golden hair and is married to the thunder god Thor.