Skagos

Skagos is an island in Game of Thrones. It is off the North Western coast of Westeros in the Bay of Seals and is part of the region known as the North. It lies south of its smaller sister island Skane.

In the books
In the Song of Ice and Fire novels Skagos is thought to be inhabited by savage cannibals who are nominally under the control of Winterfell but effectively rule themselves. The people of Skagos call themselves Skagosi, which means "Stoneborn" in the Old Tongue. Other Northmen derisively call them "Skaggs." Descendents of the First Men, Skagosi are savage, little more than tribes of raiders who are thought to be cannibals. It's said that in ancient days, men of Skagos sailed to Skane, seizing all the women, killing all the men, and feasting on their hearts and livers for a fortnight leaving Skane uninhabited. Skagos rebelled against Winterfell 100 years prior to the events of the novels. The rebellion was suppressed but the Lord of Winterfell and hundreds of his men died in the fighting.