Louis II, known as Louis the Stammerer, was the king of Aquitaine and later the king of West Francia. He was the eldest son of Emperor Charles the Bald and Ermentrude of Orléans. Louis the Stammerer was physically weak and outlived his father by a year and a half.

The Duchy of Aquitaine was a historical fiefdom in western, central, and southern areas of present-day France to the south of the river Loire, although its extent, as well as its name, fluctuated greatly over the centuries, at times comprising much of what is now southwestern France (Gascony) and central France.