When the Andals invaded centuries later the northern lords were the only ones able to successfully hold them off, which explains why the northern gene-pool is still predominately blood from the first men. After the fighting was over a man by the name of Bran the Builder constructed a massive wall of ice to prevent any further invasions from the north, the wall eventually led to the formation of the Nights Watch. After the fighting was over The children of the forest vanished from society, never to be seen again. The children and the men eventually formed an alliance with each other in order to fight against the white walkers that they had created, and in doing so successfully vanquished the white walkers, for a time. Eventually the children created the white walkers as a means of defense against the humans that fought against them, but the walkers proved a greater threat than the men themselves. The Northern kingdoms fought a long and bloody war against The children of the forest. The North is the oldest of all of the kingdoms, descending from the First Men after they fled from beyond the wall.
