Martin, George R.R. Fire and Blood (0008307733)
Set centuries before the events in A Song of Ice and Fire, FIRE AND BLOOD is the definitive history of the Targaryens in Westeros as told by Archmaester Gyldayn, chronicling the conquest that united the Seven Kingdoms under Targaryen rule through to the Dance of the Dragons: the Targaryen civil war that nearly ended their dynasty forever.