Urri Greyjoy

Lineage
Urri the Young, First Lord of the joined Kingdoms of the North and Iron Islands and heir to both the Great Houses of Stark and Greyjoy sounds more important than he in actuality was. Urri Greyjoy was the heir concieved out of the union between Lord Haatack Stark's daughter and Lord Balon Greyjoy II. As Lord Haatack's daughter was his only heir, this meant the marriage would legally result in a joined kingdom over which the next generations would rule. Urri Greyjoy was the first and currently the only heir of this new lineage and took his seat at only 14 years old after the death of his father and mother.

Impact
Urri Greyjoy reigned over the North and Iron Islands during the Third Clash and found himself at the center of much intrigue in the Capitol after the death of          King Stannis II. Working mostly alongside the Great Council with Juon Dondarrion and the Princess of Dorne, Urri Greyjoy was mostly used a fallguy for the crimes of the Great Council. Young and naïve, Urri had been tasked with buying the Wildfyre which would eventually be used by the Great Council to blow up the second Sept of Baelor and storing the Dragoncaller Horn in the Winterfell Crypts, stolen by the Great Council to prevent a dragon from being summoned by Lord Bron Tyrell III of the Reach.

The Dragoncaller Horn
With tensions heating up in the Capitol with the Peasant Revolt after the death of Lord Arryn and the destruction of the Sept of Baelor at the hands of the Great Council, Urri came to realise what artifact the council had him store in Winterfell. No child at that age could resist the chance to see a real dragon, especially since they hadn't been seen since the days before Bran the Broken. So with this in mind and against all warning of his advisors, Urri Greyjoy send the horn back to the Lord of the Reach resulting in the Second Tragedy at Summerhal and the birth of the Last Dragon. Urri never actually got to see the dragon in person, which brought him massive amounts of sadness resulting in him refusing to eat his vegetables for atleast 2 weeks, sources vary.