Why The Night King In Game Of Thrones Is Almost Definitely A Stark

The official histories of the Seven Kingdoms, as represented in The World of Ice and Fire, speculate that the Night's King likely came from one of the Northern families, saying he could have been "...a Bolton, a Woodfoot, an Umber, a Flint, a Norrey, or even a Stark, depending on where the tale is told."

But when Old Nan told the story to Bran, as he recalls in A Storm of Swords, she said, "Some say he was a Bolton. Some say a Magnar out of Skagos, some say Umber, Flint, or Norrey. Some would have you think he was a Woodfoot, from them who ruled Bear Island before the ironmen came. He never was. He was a Stark, the brother of the man who brought him down."

The suggestion that the Night's King was the brother of the Lord of Winterfell certainly has a significant impact on the current Night King's relationship to the Starks of our story.