House Stark is one of the most ancient and noblest houses in Westeros, having ruled the continent all the way from the Neck to the southern edge of the Frostfang mountains since the First Men settled The North. Gradually, inexorably, like the progress of a glacier, the Starks have subdued and won as bannermen all of the other Great Houses of The North. Glovers, Tallharts, Reeds, Umbers, Hornwoods, Mormonts and more have all bent the knee to the might of the House Stark over the centuries, and even the stubborn House Bolton has been subdued for generations.
The Lord of House Stark holds the title King of Winter, and rules The North from their home and seat at Winterfell. More than any other of the Seven Kingdoms, The North remembers the truly ancient ways and traditions of the First Men that settled Westeros and formed The Pact with the Children of the Forest and the giants, and more than any other House in The North, the Starks embody this ideal. They are known to be firm and unyielding in matters of law, yet fair and honorable. They do not shirk from unpleasant details of duty, and take seriously their responsibility to keep The North hale and whole.
In recent generations, House Stark has become less prolific than in prior centuries. Some have pointed towards the last two Queens of Winter, a Mormont and a Reed, and noted that their families have never been overlarge, but none truly knows what the cause may be. Certainly over the span of millennia, any family may experience a generation or three of fewer children, but the result for the Starks at present is that when the current King of Winter, Gaven Stark inherited the title from his father Lord Robert, he was the only heir to the family line save for his notorious cousin Brandon Stark (although less well-known then as opposed to now, Brandon already had a reputation as a confirmed bachelor, prodigious drinker, and eccentric enthusiast for unusual scholarly topics). Add to these stresses the fact that The North was in the deep throes of the Longest Night, and it will seem all the more staggering that Lord Gaven and Lady Katy produced six sons and two daughters in eleven years.
Although this may have seemed a boon, it proved to breed further tragedy. When the King of Winter set off into the wilderness to treat with the Children of the Forest and seek out their aid in defeating The Others, he took all of his sons with him, from his eldest and heir Robert down to eight year-old Brynden. Not a single one of his boys returned, and Gaven Stark himself seemed to have aged a decade in the months that he was absent.
House Stark now stands in no small amount of peril. The King of Winter and his Queen are both growing older, both in years and in strain and sorrow, and the King’s cousin Brandon is now sworn to The Night’s Watch. No heir currently stands to replace King Gaven when his reign has ended, and House Bolton has begun stirring from the Dreadfort, issuing rumbles that hint at rebellion. Twice before in history have the Boltons overthrown the Starks for a time as Kings of Winter, and it would seem that they may feel that a third attempt is merited sooner rather than later.