Louis was born in the heartlands of West Francia's Carolingian lands between Laon and Reims in 920 or 921. From his father's first marriage with Frederuna (d. 917) he had six half-sisters. He was the only male heir to the throne.
After the dethronement and capture of Charles the Simple in 923, following his defeat at the Battle of Soissons, queen Eadgifu and her infant son took refuge in Wessex (for this he received the nickname of d'Outremer) at the court of her father King Edward, and after Edward's death, of her brother King Æthelstan. Young Louis was raised in the Anglo-Saxon court until his teens. During this time he enjoyed legendary stories about Edmund the Martyr, King of East Anglia, an ancestor of his maternal family who had heroically fought against the Vikings.
Louis became the heir to the western branch of the Carolingian dynasty after the death of his captive father in 929, and in 936, at the age of 15, was recalled from Wessex by the powerful Hugh the Great, Margrave of Neustria, to succeed the Robertian king Rudolph who had died.
Once he took the throne, Louis wanted to free himself from the tutelage of Hugh the Great, who, with his title of Duke of the Franks was the second most powerful man after the King.
In 939, the young monarch attempted to conquer Lotharingia; however, the expedition was a failure and his brother-in-law, king Otto I of East Francia counterattacked and besieged the city of Reims in 940. In 945, following the death of William I Longsword, Duke of Normandy, Louis tried to conquer his lands, but was kidnapped by the men of Hugh the Great.
The Synod of Ingelheim in 948 allowed the excommunication of Hugh the Great and released Louis from his long tutelage. From 950 Louis gradually imposed his rule in the northeast of the kingdom, building many alliances (especially with the Counts of Vermandois) and under the protection of the Ottonian kingdom of East Francia.