Louis III was the king of West Francia from 879 until his death in 882. The eldest son of king Louis the Stammerer and his first wife Ansgarde of Burgundy, he succeeded his father and ruled jointly with his younger brother Carloman II, who became sole ruler after Louis's death. Louis's short reign was marked by military success.
Louis was born while his father was King of Aquitaine and his grandfather Charles the Bald was ruling West Francia. Some doubts were raised about his legitimacy, since his parents had married secretly and Ansgarde was later repudiated at Charles' insistence. When Charles died in 877 and then Louis the Stammerer died two years later, some Frankish nobles advocated electing Louis as the sole king, but another party favoured each brother ruling a separate part of the kingdom. In September 879 Louis was crowned at Ferrières Abbey. In March 880 at Amiens the brothers divided their father's kingdom, Louis receiving the northern part, called Neustria or sometimes simply Francia.
Louis III died on 5 August 882 at Saint-Denis in the centre of his realm, having hit his head and fallen from his horse while chasing a girl with amorous intent. He hit the lintel of a door with his head while mounting his horse and fractured his cranium on impact, which led to his death. Since he had no children, his brother Carloman II became the sole king of West Francia and the victor of Saucourt was buried in the royal mausoleum of the Basilica of St Denis.