LOUIS The PIOUS, King of the Franks b 778

Louis the Pious (778 – 20 June 840), also called the Fair, and the Debonaire,[1] was the King of the Franks and co-Emperor (as Louis I) with his father, Charlemagne, from 813. He was also King of Aquitaine from 781.  

As the only surviving adult son of Charlemagne and Hildegard, he became the sole ruler of the Franks after his father’s death in 814, a position which he held until his death, save for the period 833–34, during which he was deposed.  

During his reign in Aquitaine, Louis was charged with the defence of the empire’s southwestern frontier. He conquered Barcelona from the Muslims in 801 and asserted Frankish authority over Pamplona and the Basques south of the Pyrenees in 812. As emperor he included his adult sons, Lothair, Pepin, and Louis, in the government and sought to establish a suitable division of the realm among them. The first decade of his reign was characterised by several tragedies and embarrassments, notably the brutal treatment of his nephew Bernard of Italy, for which Louis atoned in a public act of self-debasement.  

In the 830s his empire was torn by civil war between his sons, only exacerbated by Louis’s attempts to include his son Charles by his second wife in the succession plans. Though his reign ended on a high note, with order largely restored to his empire, it was followed by three years of civil war. Louis is generally compared unfavourably to his father, though the problems he faced were of a distinctly different sort. 

Louis was born while his father Charlemagne was on campaign in Spain, at the Carolingian villa of Cassinogilum, according to Einhard and the anonymous chronicler called Astronomus; the place is usually identified with Chasseneuil, near Poitiers.[2] He was the third son of Charlemagne by his wife Hildegard. His grandfather was King Pepin the Younger.

Louis was crowned King of Aquitaine as a child in 781[3] and sent there with regents and a court. Charlemagne constituted the sub-kingdom in order to secure the border of his kingdom after the destructive war against the Aquitanians and Basques under Waifer (capitulated c. 768) and later Hunald II, which culminated in the disastrous Battle of Roncesvalles (778). Charlemagne wanted his son Louis to grow up in the area where he was to reign. However, in 785, wary of the customs his son may have been taking in Aquitaine, Charlemagne sent for him to Aquitaine and Louis presented himself at the Royal Council of Paderborn dressed up in Basque costumes along with other youths in the same garment, which may have made a good impression in Toulouse, since the Basques of Vasconia were a mainstay of the Aquitanian army.

In 794, Charlemagne settled four former Gallo-Roman villas on Louis, in the thought that he would take in each in turn as winter residence: Doué-la-Fontaine in today’s Anjou, Ebreuil in Allier, Angeac-Charente, and the disputed Cassinogilum. Charlemagne’s intention was to see all his sons brought up as natives of their given territories, wearing the national costume of the region and ruling by the local customs. Thus were the children sent to their respective realms at so young an age. Each kingdom had its importance in keeping some frontier, Louis’s was the Spanish March. In 797, Barcelona, the greatest city of the Marca, fell to the Franks when Zeid, its governor, rebelled against Córdoba and, failing, handed it to them. The Umayyad authority recaptured it in 799. However, Louis marched the entire army of his kingdom, including Gascons with their duke Sancho I of Gascony, Provençals under Leibulf, and Goths under Bera, over the Pyrenees and besieged it for two years, wintering there from 800 to 801, when it capitulated.[4] The sons were not given independence from central authority, however, and Charlemagne ingrained in them the concepts of empire and unity by sending them on military expeditions far from their home bases. Louis campaigned in the Italian Mezzogiorno against the Beneventans at least once. 

Louis was one of Charlemagne’s three legitimate sons to survive infancy. He had a twin brother, Lothair who died during infancy. According to Frankish custom, Louis had expected to share his inheritance with his brothers, Charles the Younger, King of Neustria, and Pepin, King of Italy. In the Divisio Regnorum of 806, Charlemagne had slated Charles the Younger as his successor as emperor and chief king, ruling over the Frankish heartland of Neustria and Austrasia, while giving Pepin the Iron Crown of Lombardy, which Charlemagne possessed by conquest. To Louis’s kingdom of Aquitaine, he added Septimania, Provence, and part of Burgundy. However, Charlemagne’s other legitimate sons died – Pepin in 810 and Charles in 811 – and Louis alone remained to be crowned co-emperor with Charlemagne in 813. On his father’s death in 814, he inherited the entire Frankish kingdom and all its possessions (with the sole exception of Italy, which remained within Louis’s empire, but under the direct rule of Bernard, Pepin’s son).

https://en.wikipedia.org/wiki/Louis_the_Pious