Let us leave Louis the Debonnair his traditional name, although it is not an exact rendering of that which was given him by his contemporaries.  They called him Louis the Pious.  And so indeed he was, sincerely and even scrupulously pious; but he was still more weak than pious, as weak in heart and character as in mind, as destitute of ruling ideas as of strength of will; fluctuating at the mercy of transitory impressions, or surrounding influences, or positional embarrassments.  The name of Debonnair is suited to him; it expresses his moral worth and his political incapacity, both at once.

As king of Aquitania, in the time of Charlemagne, Louis made himself esteemed and loved; his justice, his suavity, his probity, and his piety were pleasing to the people, and his weaknesses disappeared under the strong hand of his father.  When he became emperor, he began his reign by a reaction against the excesses, real or supposed, of the preceding reign.  Charlemagne’s morals were far from regular, and he troubled himself but little about the license prevailing in his family or his palace.  At a distance he ruled with a tight and a heavy hand.  Louis established at his court, for his sisters as well as his servants, austere regulations.  He restored to the subjugated Saxons certain of the rights of which Charlemagne had deprived them.  He sent out everywhere his commissioners (missi dominici) with orders to listen to complaints and redress grievances, and to mitigate his father’s rule, which was rigorous in its application, and yet insufficient to repress disturbance, notwithstanding its preventive purpose and its watchful supervision.

Almost simultaneously with his accession, Louis committed an act more serious and compromising.  He had, by his wife Hermengarde, three sons, Lothaire, Pepin, and Louis, aged respectively nineteen, eleven, and eight.  In 817 Louis summoned at Aix-la-Chapelle the general assembly of his dominions; and there, whilst declaring that “neither to those who were wisely-minded, nor to himself, did it appear expedient to break up, for the love he bare his sons and by the will of man, the unity of the empire, preserved by God himself,” he had resolved to share with his eldest son, Lothaire, the imperial throne.  Lothaire was in fact crowned emperor; and his two brothers, Pepin and Louis, were crowned king, “in order that they might reign, after their father’s death and under their brother and lord, Lothaire, to wit:  Pepin, over Aquitaine and a great part of Southern Gaul and of Burgundy; Louis, beyond the Rhine, over Bavaria and the divers peoplets in the east of Germany.”  The rest of Gaul and of Germany, as well as the kingdom of Italy, was to belong to Lothaire, emperor and head of the Frankish monarchy, to whom his brothers would have to repair year by year to come to an understanding with him and receive his instructions.  The last-named kingdom, the most considerable of the three, remained under the direct government of Louis the Debonnair, and at the same time of his son Lothaire, sharing the title of emperor.  The two other sons, Pepin and Louis, entered, notwithstanding their childhood, upon immediate possession, the one of Aquitaine and the other of Bavaria, under the superior authority of their father and their brother, the joint emperors.