[Image:U 861, Norsta.jpg|200px|thumb|right|The
Norsta Runestone (U 861) on the drive of
Wik Castle outside
Uppsala was probably made by Sweyn and his family, as it mentions two people called Sweyn and Møy. It is the only existing mention of a Møy ("maiden") besides the mention of Sweyn's sister
Mær (the Old Icelandic form of
Møy) in
Hervarar saga, and it is contemporary with Sweyn.]]
Sweyn (,
Sweyn the Sacrificer) was a
Swedish king c. 1080, who replaced his Christian brother-in-law
Inge as
King of Sweden, when Inge had refused to administer the
blóts (pagan sacrifices) at the
Temple at Uppsala. There is no mention of Sweyn in the regnal list of the
Westrogothic law, which suggests that his rule did not reach
Västergötland. According to Swedish historian Adolf Schück he was probably the same person as
Håkan the Red and was called the
Blót Swain (a
swain who was willing to perform the blót) as an epithet rather than a personal name.