Louis and his court are crossing a wooden gallery from the cathedral to the palace in Aachen on Maundy Thursday 817, when the gallery collapses, killing many.

Louis, having barely survived and feeling the imminent danger of death, begins planning for his succession; three months later he issues an Ordinatio Imperii, an imperial decree that lays out plans for an orderly succession.

He had already given his two eldest sons a share in the government in 815, when he had sent his elder sons Lothair and Pepin to govern Bavaria and Aquitaine respectively, though without the royal titles.

Now, he proceeds to divide the empire among his three sons and his nephew Bernard of Italy: Lothair is proclaimed and crowned co-emperor in Aachen by his father.

He is promised the succession to most of the Frankish dominions (excluding the exceptions below), and will be the overlord of his brothers and cousin.

Bernard, the son of Charles's son Pippin of Italy, is confirmed as King of Italy, a title he had been allowed to inherit from his father by Charles.

Pepin is proclaimed King of Aquitaine, his territory including Gascony, the march around Toulouse, and the counties of Carcassonne, Autun, Avallon and Nevers.

Louis, the youngest son, is proclaimed King of Bavaria and the neighboring marches.

If one of the subordinate kings dies, he is to be succeeded by his sons.

If he dies childless, Lothair will inherit his kingdom.

In the event of Lothair dying without sons, one of Louis the Pious' younger sons will be chosen to replace him by "the people".

Above all, the Empire will not be divided: the Emperor will rule supreme over the subordinate kings, whose obedience to him is mandatory.

With this settlement, Louis tries to combine his sense for the Empire's unity, supported by the clergy, while at the same time providing positions for all of his sons.

Instead of treating his sons equally in status and land, he has elevated his first-born son Lothair above his younger brothers and given him the largest part of the Empire as his share.

Atlantic West Europe, 820–831: Dynastic Consolidation and Carolingian Stability

Between 820 and 831, Atlantic West Europe—which included Brittany, Aquitaine, Normandy, Burgundy, central France, Alsace, Franche-Comté, and the Low Countries—experienced a period of relative stability under Carolingian rule, although internal tensions foreshadowed future divisions.

Political and Military Developments

• Carolingian Empire: Rule of Louis the Pious

  • Louis the Pious (r. 814–840) continued to govern the vast Carolingian Empire from Aachen, maintaining imperial unity but increasingly challenged by succession disputes among his sons.
  • Attempts to provide inheritance for his sons (Lothair, Pepin I of Aquitaine, Louis the German, and Charles the Bald) initiated complex internal dynamics, undermining central authority.

• Aquitaine: Semi-Autonomous Rule

  • Pepin I, as King of Aquitaine (817–838), enjoyed substantial regional autonomy, laying the foundations for Aquitaine’s distinct political identity within the empire.

• Brittany: Independent Struggles

  • Brittany, under Nominoë, asserted independence from Frankish overlordship, beginning a protracted struggle for autonomy that characterized much of the ninth century.

Economic and Social Developments

• Carolingian Economic Stability
  • The Carolingian economic renaissance continued from Charlemagne’s era, with sustained agricultural productivity, trade, and monetization, supporting urban growth, particularly around key centers such as Tours, Orléans, and Nantes.

Religious and Cultural Developments

• Monastic and Intellectual Continuity

  • Monasteries, notably Saint Martin of Tours, preserved and expanded their cultural and intellectual role, copying manuscripts and promoting Carolingian learning and literacy.

• Continued Carolingian Renaissance

  • The Carolingian Renaissance's cultural flowering continued, fostering artistic and literary works, scriptoria productivity, and scholarly efforts, particularly in monastic centers.

Legacy

This era provided stability but also revealed underlying dynastic fragility that would soon lead to fragmentation, notably in the coming disputes among Louis the Pious's heirs. Atlantic West Europe enjoyed a continuation of Carolingian cultural and economic flourishing, even as seeds of political division were sown.

Problems had commenced on the southwestern frontier early in the reign of Louis the Pious, Roman Emperor and King of the Franks from 814, with the deposition in 815 of Séguin, Duke of Vasconia, which had sparked a widespread rebellion, led by Gartzia Semeno (García I Jiménez), Seguin’s son.

Gartzia had been succeeded at his death in 818 by his son Lupus III Centule.

Louis’s second son Pepin, who had in 817 received the Kingdom (within the Empire) of Aquitaine, had sent Berengar of Toulouse and Guerin of Provence against Lupo in 819 , as recorded by both the Annales regni Francorum and the Vita Hludowici; defeating him, Pepin installs Aznar Sanchéz, a count of local provenance, in his place.

Carolingian authority is thus restored in Vasconia, but not across the Pyrenees in Navarre.

Agobard, archbishop of Lyon from 816, writes against the Adoptionist heresy—i.e., that Jesus was not the son of God by nature but by adoption—of Felix of Urge, who had been confined at Lyon from 800 to 818, and against the Jews.

In 820, he “proves” that Jews are born slaves and accursed.

He forcibly converts Jewish children, offering them and their parents no choice in the matter; the “choice” of expulsion is, for the first time in Carolingian domains, not an option.

Agobard's anti-Jewish essays, a few of which survive, are systematically aimed at humiliating and eradicating Francia’s Jewish community, referring to Jews as "sons of darkness".

In his writings against popular superstitions, he denounces the trial by ordeal of fire and water, the belief in witchcraft, and the ascription of tempests to magic, maintains the Carolingian opposition to image-worship, but carries his logic farther and opposes the adoration of the saints.

In his purely theological works, Agobard is strictly orthodox, denying the verbal inspiration of Scripture.

As many clerics, Agobard is a proponent of the unity of the Frankish Empire.

Hence, he opposes the Empress Judith's initiatives on behalf of her son Charles the Bald and supports the rebellion of Charles' half-brothers Lothair and Pepin against their father, Emperor Louis “the Pious”, the son and successor of Charlemagne and the fourth monarch of the Carolingian dynasty.

The Carolingians, late in the eighth or early in the ninth century, had created the County of Aragon or Jaca, a small Frankish marcher county in the central Pyrenean valley of the Aragon river, comprising Ansó, Echo, and Canfranc and centered on the small town of Jaca (Iacca in Latin and Chaca in Aragonese).

Originally intended to protect the central Pyrenean passes from the Moors in the same way that the Duchy of Vasconia and the Marca Hispanica are to protect the west and east, Aragon remains largely out of the reach of its nominal Carolingian lords, though it is an expressly Frankish creation and not an ethnically distinct region.

The earliest attested local ruler is Oriol, or Aureolus (807), probably either Frankish or Visigothic.

That Aragon is a combined creation of Frankish efforts at reconquest and the activity of the local Hispano-Visigothic elite to unite the rural populace against the Moors of the Ebro valley seems assured.

Aznar Galíndez I, the Count of Aragon and Conflent from 809 and Cerdanya and Urgell from 820, had succeeded Aureolus as count of the valley of the River Aragón on the latter's death in 809.

Some sources indicate him as count of Jaca, which is probably the seat of his authority within the valley.

Installed by the King of Aquitaine, Pepin I, he has remained a Frankish vassal.

In 820, however, he apparently abandons his Frankish benefactors and allies with the Basques to fight the Ebro valley’s Banu Qasi family of Muladis, local magnates converted to Islam that have manages to be independent of the emirs.

García, the son of Galindo Belascotenes, had married Matrona, the daughter of Aznar Galíndez.

However, according to tradition, García had taken offense at a prank played on him by his brothers-in-law, Centule and Galindo, who had locked him in a house during the Hogueras de San Juan.

In retaliation, he had murdered Centule and repudiated Matrona, allying himself with Íñigo Arista of Pamplona, whose daughter he had then married.

His role in these events led to his traditional nickname, 'the Bad'.

Íñigo, gathering a small army, deposes Aznar, making García count of Aragon and Conflent.

Lothair, Emperor Louis’ eldest son by Ermengarde, is the heir to the entire Carolingian Empire, but has to share it with his brothers because of the traditional Frankish practice of division of patrimonies among all surviving sons.

Lothair had probably passed his early life at the court of his grandfather Charlemagne, until 815 when he became king of Bavaria.

When Louis divided the Empire between his sons in 817, Lothair had been crowned joint emperor at Aix-la-Chapelle (Aachen) and given a certain superiority over his brothers, Pepin and Louis, who had respectively received Aquitaine and Bavaria.

Lothair was also given the Iron Crown of Lombardy, then still held by Louis the Pious' nephew Bernard.

After Bernard’s death, Lothair had received the Italian kingdom.

In 821, he had married Ermengarde, daughter of Hugh, count of Tours, and in 822 assumed the government of Italy.

On April 5, 823, he had been crowned co-emperor again by Pope Paschal I, this time at Rome.

In November 824, he promulgates a statute concerning the relations of pope and emperor which reserves the supreme power to the secular potentate, and from this time he is to issue various ordinances for the good government of Italy.

Valentine succeeds Eugene II to the papacy in 827 but dies thirty or forty days after after taking office.

Gregory IV, chosen to succeed Valentine in December 827, had recognized the supremacy of the Frankish emperor in the most unequivocal manner, but papal dependence on the Roman Emperor has loosened through the quarrels of Louis and his sons.

In the sons' rebellion against their father, Gregory supports Lothair, hoping his intervention would promote peace, but in practice this action annoys the Frankish bishops.

Gregory's response is to insist upon the primacy of St. Peter's successor, the papacy being superior to the Emperor.

The Accusation Against Bernard of Septimania and the 830 Revolt

Bernard of Septimania, one of Louis the Pious’ closest advisors, finds himself at the center of court intrigue and dynastic conflict in the early 9th century.

According to Thegan of Trier’s Gesta Hludowici, Bernard is accused of having an illicit relationship with Empress Judith of Bavaria, Louis’ second wife. Thegan dismisses these claims as lies, but the rumors spread widely, intensifying political tensions at court.

The April 830 Riot at Rennes

By April 830, Louis the Pious' sons—Lothair, Pepin, and Louis the German—oppose their father’s rule, believing that Empress Judith and her allies (including Bernard) hold too much influence at court.

• While the Frankish army is gathered at Rennes to fight the Bretons, the rumors trigger unrest among the soldiers.
• A riot erupts, fueled by resentment toward Bernard and the Empress, reflecting the wider dynastic struggle between Louis and his rebellious sons.
• Facing serious threats to his life, Bernard flees the court, abandoning his position.

Bernard’s Fall from Power

• According to the Annales Bertiniani, Bernard returns to Barcelona, where he had previously served as Count of Barcelona and Margrave of Septimania.
• His brother, Eribert, who remained at court, is banished.
• Bernard is deprived of the County of Autun, a title he had held for some time.

The Aftermath: Dynastic Conflicts Continue

Bernard’s fall from favor marks a turning point in the struggles between Louis the Pious and his rebellious sons. Over the next decade, these dynastic conflicts will further destabilize the Carolingian Empire, leading to civil wars, shifting alliances, and the eventual fragmentation of the empire under the Treaty of Verdun (843).

Judith of Bavaria, Louis's second wife, had won the consent of her stepson Lothair on his return to his father's court,to her plan for securing a kingdom for her son Charles, a scheme that had been implemented in 829 when the young prince was given Alemannia as king.

Lothair, however, soon changes his attitude.

In Gascony and the chronically troublesome Pyrenees borderlands, Counts Hugh and Matfrid have failed to support the Louis’s military efforts, and the emperor has summarily stripped them of their positions.

This forceful action and a growing resentment of the efforts of Judith on behalf of her seven-year-old son, the target of resentment by his three adult half brothers, is the cause of a growing dispute between Louis and his son and coemperor, Lothair.

The quarrel over Charles’ future inheritance leads in 830 to open conflict.

Pepin, Louis the German, and Lothair, aided by Hugh and Matfrid, seek to “free”; the emperor from the tyranny of the “jezebel” Judith, but Louis's supporters, sowing discord among his elder sons, in October 830 restore him to authority.

The abortive coup claims a victim, however, when the Ordinatio imperii is replaced by a new Divisio regnorum, which calls for a division of the empire into four approximately equal kingdoms that are to become independent upon Louis's death, thus restoring the traditional Frankish practice of succession.

Supporters of a unified empire agitate against the Divisio, while the involvement of opportunistic nobles exacerbated the continuing conflict among the brothers.