Many of us are familiar with the Christmas ham and New Year’s Resolutions but have you ever stopped to ask yourself where these customs come from? That’s right, they originated with us. The Christmas ham comes from the sonargöltr, or sacrificial boar, and New Year’s Resolutions are a pale reflection of heitstrenging, holy and powerful oaths sworn upon the bristles and / or head of the sonargöltr.
Hervarar saga ok Heiðreks makes reference to the custom of swearing oaths while placing a hand on the bristles of a boar that would later be sacrificed during blót. Helgakviða Hjörvarðssonar also discusses the act of swearing oaths on the sacrificial boar and adds that it is done during the drinking of the bragarfull. Ynglinga saga adds that the boar was also used for divination.
These oaths were called heitstrenging. While some of the vows spoken are portrayed as insignificant or silly, the vast majority of the vows given in the sagas are treated very seriously and there were significant penalties for failing to keep them. Jómsvíkinga saga gives an example of one of the most violent and severe oaths taken by the followers of Sweyn Forkbeard. Harald Fairhair gets his nickname from his oath not to comb his hair until he has conquered all of Norway.
The choice of a sacrificial boar shows a connection to Freyr, particularly through his sacred boar Gullinbursti. There is a good bit of evidence regarding sacrifices to Freyr during Yule for the blessing of a less harsh winter. Jan de Vries also connects a Swedish custom of eating pig shaped cakes at Christmas to ancient Heathen practices, particularly the sonargöltr (Altgermanische Religionsgeschichte, Volume 1). In Teutonic Mythology, Jakob Grimm connects the serving of a boar’s head at banquets to this ancient practice of the boar sacrifice.
Update: Vertyx from Reddit mentioned that the pig cakes de Vries is refering to may actually be marsipangrisar, a candy pig made from Marzipan. As a child I saw these only rarely and didn’t connect them to what de Vries was writing about. A quick look around the internet refers to the Marzipan pigs as a confection that is said to bring good luck. I find it interesting that we see yet another surviving element of our past in modern traditions. My thanks to Vertyx from bringing this up.