Louis the Pious is one of the three legitimate sons of Charles I, including his twin brother, Lothair, to have survived 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, Charles 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 Charles possesses by conquest.

To Louis's kingdom of Aquitaine, he has added Septimania, Provence, and part of Burgundy, but in the event, Charles's other legitimate sons have died—Pepin in 810 and Charles in 811—and Louis alone remains to be crowned co-emperor with Charles in 813.

The general Leo, called the Armenian, had at first joined Bardanes Turcus but later sided with Nikephoros when the two were fighting over the imperial throne in 803.

Distinguishing himself as a general under Nikephoros and Michael, Leo has become strategos (“general”) of the Anatolikon district of the empire.

Michael defeats the Bulgarians in several engagements in which Leo takes part, but on June 22, 813, the emperor loses the Battle of Versinikia near Adrianople.

Krum seizes Adrianople and moves some fifty thousand captives to the Bulgarian lands towards the north of the Danube.

When Michael unwisely refuses the peace terms the Bulgarians offer, the Asian troops under Leo desert.

Leo then deposes Michael and …

…replaces him as Leo V in July.

Michael retires to a monastery on one of the Princes Islands.

The way opened for further Bulgar victories, Krum besieges Constantinople in 813 and devastates the surrounding countryside.

Harthama ibn A'yan had been in Samarkand when al-Rashid died at Tus in March 809, and remained in the east after.

Consequently he had thrown in his lot with al-Ma'mun in the civil war against al-Amin, and is along with Tahir ibn Husayn one of the two commanders of al-Ma'mun's army during the crucial year-long siege of Baghdad.

During the siege Harthama leads the attack from the east while Tahir commands from the west.

In the final stage of the siege, Harthama tries unsuccessfully to secure the surrender and life of al-Amin, who has in the meantime been declared deposed as caliph in Iraq and Arabia, by sending a boat to ferry him over the Tigris.

The boat, however, capsizes, and al-Amin is captured and executed by Tahir's men, contrary, it seems, to al-Ma'mun's orders, on September 24 or 25, 813.

The father of Hassan ibn Sahl was an Iranian Zoroastrian convert to Islam.

Along with his brother, the future vizier al-Fadl ibn Sahl, Hasan had entered the service of the Barmakid al-Fadl ibn Yahya in the reign of Harun.

During the civil war, he has been entrusted with the supervision of the land tax (kharaj) office.

After Ma'mun's troops capture the caliphal capital, Baghdad, Hasan is sent west to assume the governance of Iraq, while Ma'mun and Fadl remain in Marv.

Al-Ma'mun rules from 813 as the recognized caliph, but Egypt, Syria, and Mesopotamia begin to slip from central control.

Halfdan the Mild may have won independence for Vestfold during the turbulent years of 813–14, according to the historian Halvdan Koh.

The Frankish annals state that the kings of Hedeby had to solve an uprising in Vestfold at this time.

Halfdan’s people, according to Ynglingatal, "gained victory" in this uprising, and Halfdan is thus the first independent ruler of Vestfold.

The city of Kannuaj remains a focal point for the age’s three powerful Indian dynasties, namely the Gurjara Pratiharas of Malwa, the Palas of Bengal and the Rashtrakutas of the Deccan.

The so-called tripartite struggle began with the defeat of Indrayudh at the hands of Gurjar Pratihar ruler Vatsaraja.

The Pala ruler Dharampala is also keen to establish his authority at Kannauj, giving rise to a struggle between Vatsaraja and Dharampala.

Dharampala was however defeated.

Taking advantage of the chaos, the Rashtrakuta ruler Dhruva had surged northwards, defeated Vatsaraja, and taken Kannauj for himself, completing the furthest northern expansion by a South Indian ruler.

When the Rashtrakuta ruler withdrew southward, Dharampala was left in control of Kannauj for some time.

The struggle between the two northern dynasties continued: the Pala Chakrayudh, the incumbent puppet ruler of Kannauj, had been defeated by the Pratihara Nagabhata II, and Kannauj was again occupied by the Gurjar Pratihars.

Dharampala had tried to take control of Kannauj but had been soundly defeated at Moongher by the Gurjar Pratihars.

Nagabhata II was in turn defeated by the Rashtrakuta Govinda III, who had initiated a second northern surge.

An inscription states that Chakrayudh and Dharampala had invited Govinda III to war against the Gurjar Pratihars, but Dharampala and Chakrayudh had both submitted to Govinda III, in order to win his sympathy.

After this defeat, Pratihara power had degenerated for some time, but following the death of Dharampala in 810, Nagabhata II regains his hold over Kannuaj.

He moves his capital here from Ujjain in 813.

During this period, the Rashtrakutas face internal conflicts, and neither they nor the Palas contest the move.

The Gurjar Pratihars are now the greatest power in North India.

Pro-Greek reaction to the Veneto-Frankish alliance under the doges of the Parteciaco family leads to the transfer of the seat of government from the island of Malamocco (now Lido) to the Rialto group of islands, by now the center for exiles in the factional fighting, and where where political independence could be more easily maintained.

Agnello Participazio’s Rialtine house on the Campiello della Cason becomes the first doge's palace in Venetian history and he soon begins expanding it in stone.

However, no traces remains of that ninth century building, owing to the partial destruction of the palace by a fire in the tenth century.

His reign begins on a happy note.

By the Pax Nicephori, Venetia is retained by the Constantinople and renounced by Charles I of the Franks, but its practical independence is affirmed.

Though the Franco-Greek treaty of 814 guarantees to Venice political and juridical independence from the rule of the Western Empire, it does not confirm any effective dependence on Constantinople.

Agnello begins the minting of the first Venetian coinage.

Louis the Pious Learns of Charlemagne’s Death (814)

On January 28, 814, Louis the Pious, King of Aquitaine, is residing at his villa in Doué-la-Fontaine, Anjou, when he receives news of the death of his father, Charlemagne. This moment marks the end of the reign of the greatest Carolingian ruler and the beginning of a new era for the Frankish Empire.

Unlike Charlemagne, who had ruled as both a warrior and administrator, Louis would face internal dynastic struggles, noble revolts, and external pressures, setting the stage for the eventual fragmentation of the Carolingian Empire. His reign would be defined not only by religious devotion and reforms but also by the challenge of maintaining the unity of his father's vast empire.

Charles, who stands out as an administrator for his many reforms—monetary, governmental, military, cultural, and ecclesiastical—is the main protagonist of the "Carolingian Renaissance."

At the death of Charles on January 814, his son Louis the Pious, hurrying to Aachen, he crowns himself and is proclaimed by the nobles with shouts of Vivat Imperator Ludovicus.

Louis assumes sole control of the entire Frankish empire, now extending from Catalonia in the west to Saxony in the east (with the sole exception of Italy, which remains within Louis's empire, but under the direct rule of Bernard, Pepin's son).

Louis also inherits his father’s troubles with invading Vikings, raiding Muslims, and an avaricious nobility.

The Carolingian empire will last only another generation in its entirety; its division, according to custom, between Louis's own sons after their father's death will lay the foundation for the modern state of Germany.

In his first coinage type, minted from the start of his reign, he imitates his father's portrait coinage, giving an image of imperial power and prestige in an echo of Roman glory.

He quickly enacts a "moral purge", in which he sends all of his unmarried sisters to nunneries, forgoing their diplomatic use as hostage brides in favor of the security of avoiding the entanglements that powerful brothers-in-law might bring.

He spares his illegitimate half-brothers and tonsures his father's cousins, Adalard and Wala, shutting them up in Noirmoutier and Corbie, respectively, despite the latter's initial loyalty.

Leo deposes Patriarch Nikephoros in 815 and convokes a synod for the following month that reimposes the decrees of the Iconoclast synod of Hieria of 754, which had opposed the use of icons.