Excerpts from Books and Wikipedia
"Sometime during his reign Harald erected a large carved stone at a place called Jelling. It was sited close to the burial mound of his father, Gorm, who was a pagan. One face of the stone depicts Jesus Christ's Crucifixion, another bears a pagan image of a horned beast entwined with a serpent, and the third carries a long inscription in runes proclaiming Harald's conversion." [1001 Days]