In 840, Gascony had been invaded by the Northmen, however, not a single word in academic works. The reason is simple: in 1911, French historians decided that they would study the deeds of the founders of Normandy, the interesting Danes north of river Loire and ignore those of the mere Norwegian looters in the south. In other words, French historians never studied the southern part of the French battlefield. Aquitaine remained a missing piece of the invasions. In this book, I shall try to place the missing piece in the puzzle, an important piece as, behind Bayonne, the invaders saw Narbonne, a passageway to the Mediterranean prosperity. The conquest of Gascony may have been the first step of a commercial war that lasted nearly two centuries.