Despite questions of his legitimacy and challenges against his ascendance to the monarchy, Louis would prove to be an effective leader during his reign, notable for the defeat of Viking invaders at the Battle of Saucourt-en-Vimeu in August 881 that would later be immortalized in the poem Ludwigslied.

[4] Due to the fact that his parents had married secretly and Ansgarde was later repudiated at Charles' insistence, Louis' legitimacy was largely questioned during his early life.

Some Frankish nobles advocated keeping Louis as the sole king, but another party favoured each brother ruling a separate part of the kingdom.

As a result of this split, Boso, one of Charles the Bald's most trusted lieutenants and the Count of Vienne, renounced his allegiance to both brothers and appropriated the title of King of Provence.

In an extremely violent and bloody attack, according to the Annales Fuldenses, the West Frankish forces slaughtered as many as 9,000 raiders and won an important, decisive victory.

According to legend, he was chasing after a girl who was retreating to her father's house on horseback and hit his head on the lintel of a low door, taking a bad fall and breaking his skull.

[8] Louis' death was incredibly damaging to the West Frankish war against the Vikings, and despite his massive victory at Saucourt, his brother and successor could not match his level of success and died in 884.