As the Southern Kingdoms continued their endless feuds and wars , the North for the most part remained peaceful and prosperous, though not without its own troubles and bouts of infighting.
Queen Krasisa Stark was the first female ruler of the North after her father met his grisely end in the Riverlands. Though women were treated far more equally in the North than the South (save Dorne) , there were still doubts about the new queen.
Krasisa quickly proved these doubts false by ruling over what is considered one of the Golden Ages of the North . The queen invested heavily in building infrastructure , roads and cities throughout the North and was a generous patron of artists, scientists and scholars. It was she who sponsored the building of the Great Libraries of Winterfell and White Harbour and with them the creation of a new order of learned men and women to replace the Maesters (who were becoming unwelcomed in the North ). This is generally pointed out as the starts of the Northern Renaissance which would eventually spread to the south in the coming centuries
Krasisa also encouraged trade with Essos, the Summer Isles and even Dorne -even becoming a close friend to Princess Nymeria.
The Queen would die at the ripe old age of 102, and would be hailed as one of the great eight stark rulers in northern history. Her eldest daughter Saoifa would rule afterwards with her younger brother Theon as chief advisor.
Unfortunately she would have a short reign of only 3 years before dying giving birth to her son, Arrik. Her brother took over as regent for his nephew and would rule effectively (The Queen's husband at the time , Lord Wydard Manderly joined the Night's Watch out of grief for losing his wife). When the crown passed to Arrik upon being eighteenth of age , he continued much of his predecessors' sound policies though later in his reign he would make some questionable decisions not least of which was the dissolution of the Night's Watch and having the Gift and the Wall become direct property of the Winter Throne.
Whether this was for pragmatic or personal reasons (the king being known to hate the brotherhood his father left him for ), this move would have caused an uproar among the Northern lords had the king not successfully brought them to his side beforehand with land grants, money and marriage alliances.
And with the black brothers were over, those who were honest men or were sent for pretty criminals were given new lands in the Gift, some eventually becoming petty lords. The murderers and rapists were executed with Lord Aster Flint (The newly dubbed Warmaster of the Wall ) being said to take extra care to draw out the executions in revenge for what happened to his daughter.
The Wall henceforth would be manned by a new order dubbed the Snow Shields who unlike the previous watch allowed both men and women to join and permitted its members to marry and have children. The commanders on the Wall were to be appointed directly by the King in Winterfell.
Afterwards the rulerships of the succeeding three kings and queens were unremarkable with the exception of Theon IV who true to his namesake expanded and cemented Northern rule beyond the Wall up to Hardhome itself before dying to a wilding arrow.
His heir King Sevan Stark would prove to be one of the worst rulers in the history of the North if not the entirety of the Seven Kingdoms. A vicious, idiotic and self centered man he quickly set the tone for the rest of his reign by exiling or killing his brothers while keeping his sisters imprisoned where he proceeded to repeatedly rape them.
The king then proceeded to not care at all about running his kingdom and engaging in all manner of debaucheries. Marrying and divorcing noble ladies on a whim while seeing mistresses from every corner of Westeros and beyond he alienated many of his lords , while his corrupt councillors were given free reign to do as they wished. The king enjoyed the tortures and executions of anyone who displeased him in the slightest ways, even his direwolf Thice was not spared and the poor creature was a one eyes, one eared gaunt husk of a direwolf. Things came to a head when he had the Greystark heir publicly castrated.
This led to the Greystarks rebelling against the Winter Throne and starting their own kingdom, followed in quick succession by many other Stark cadets. Winterfell fell into a state of insurrection , the smallfolk being completely against this tyrant who was the anathema to everything a Stark should be. The army faced unprecedented rates of desertion and it seemed the North was doomed to splinter in what would be called "The war of the wolves".
From the East however came the exiled prince Ifan Stark with an army of mercenaries and three valyrian legions backing him. Arriving at White Harbour he was quickly proclaimed as the King of Winter and many loyalist houses flocked to his banner. With such a respectful force he either conquered or convinced the other claimants to join him in marching on Winterfell.
Ifan entered the city of Winterfell without a fight but he had to breach the fortress bearing the same name to end his mad brother. Sevan Stark who even as his few remaining allies abandoned him, still believed himself King of the North, was finally killed when Thice turned on his master at last, viciously disemboweling his master . Despite being surrounded by his Wolf Guard none interfered to save the mad monarch.
They quickly surrendered to Ifan who demoted them to the snow shields , which they accepted without issue. With a quick ceremony Ifan became the undisputed King of the North , though he had to pay a heavy price to that and this doesn't refer only to the loans he took from the Iron Bank but the colonisation rights he promised Valyria in exchange for their support. The concessions he made would haunt the rest of his reign but ultimately its generally accepted that he saved the Stark dynasty as well as sparing the North a civil war.