Omurtag of Bulgaria

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.

Krum dies suddenly on April 13, 814, during preparations for a second siege of the imperial capital.

As both countries are exhausted by the sustained military effort, peace negotiations begin.

Leo succeeds in drawing the Bulgarians back and concludes a truce with Krum's son and successor, Omortag, who agrees in order to protect the western frontiers of his Bulgarian empire against the pressures exerted by Frankish expansion under Charles and his successors.

Bulgaria also faces religious problems, as the growing number of Christians disturbs Omurtag: the Khan begins anti-Christian persecutions, to which his eldest son Enravota also falls victim.

In addition, the Bulgarians have to restore their economy following the bloody conflicts of the first decade of the century, while their capital Pliska still lies in ruins.

Omurtag sends emissaries to Constantinople to negotiate the peace in the beginning of 815.

The signing ceremony is a solemn event and performed in the presence of numerous people.

The agreement envisages that the Emperor must vow according to the pagan Bulgarian customs and Omurtag's emissaries according to the Christian laws.

The Byzantine historians, outraged by the emperor's actions, recorded that the "most Christian" ruler had to pour out water on the ground from a cup, to personally turn round horse saddles, to touch triple bridle and to lift grass high above the ground.

Another historian added that Leo V had to even cut up dogs as witnesses to his vow.

The treaty of 815 between the Empire and Bulgaria determines the boundary between the two countries and provides a thirty-year peace.

Although the treaty is in Bulgaria's favor, it is a welcome respite for Constantinople, which has had to regroup its forces after successive defeats, and which faces another round of internal turmoil because of the revival of iconoclasm.

Leo has used the breathing space to reconstruct those Thracian cities that the Bulgarians had earlier destroyed.

His work indicates the degree of Constantinople’s gradual penetration into the coastal fringes of the Balkan Peninsula, as does the number of themes organized in that same region during the early ninth century.

Emperor Leo V, called Leo the Armenian, had deposed Emperor Michael I Rangabe in 813 and had castrated Michael's sons to forestall future usurpations.

In a diplomatist move, he had written wrote a letter to Patriarch Nikephoros in order to reassure him of his orthodoxy (Nikephoros being obviously afraid of a possible iconoclasm revival).

With the iconodule policy of his predecessors associated with defeats at the hands of Bulgarians and Arabs, Leo had reinstituted Iconoclasm after deposing Nikephoros and convoking a synod at Constantinople in 815.

The emperor had used his rather moderate iconoclast policy to seize the properties of iconodules and monasteries, such as the rich Stoudios monastery, whose influential iconodule abbot, Theodore the Studite, he had exiled.

Leo has appointed competent military commanders from among his own comrades-in-arms, including Michael the Amorian and Thomas the Slav.

He has also persecuted the Paulicians.

Leo is assassinated on December 25, 820, during a Christmas service in Constantinople’s church of Hagia Sophia by friends of Michael the Amorian, whom, having incurred the suspicion of his former friend and been imprisoned on a charge of treason, Leo had condemned to death the day before, ordering him to be thrown into a furnace.

After Michael’s partisans assassinate Leo, they proclaim him Emperor Michael II.

Shortly before Michael ascends the throne, however, Thomas the Slav raises a rebellion, giving himself out to be the unfortunate Emperor Constantine VI, blinded thirty-three years earlier, who had somehow escaped blinding, and secures his coronation at the hands of the Patriarch of Antioch; this is accomplished with the willing permission of Caliph al-Ma'mun, under whose jurisdiction Antioch lies.

Thomas, standing as champion to the poor and with the support of al-Ma'mun, marches west in spring 821 at the head of a motley force of Caucasian peoples whose sole bonds are to be found in their devotion to iconodule doctrine and their hatred of Michael's Iconoclasm.

In his account of the revolt, the historian Genesius lists a variety of peoples from whom the armies of the rebel were drawn: Saracens, Abasgians, Getae, Alans, Chaldoi, Armenians, Vandals and adherents of heretical sects of the Paulicians and Athinganoi.

Within a matter of months, only two themes in Asia Minor remain loyal to Michael, and in December 821, Michael besieges Constantinople.

Omurtag, the ruler of Bulgaria from 815, known as “the Builder,” had at the beginning of his reign concluded a thirty-year peace treaty with Emperor Leo V, which is inscribed on a surviving column.

The two rulers had sworn to uphold the conditions of the treaty by each other's rites, which had scandalized the imperial court.

The treaty had determined the trajectory of the border between Constantinople and Bulgaria, the status of the Slavic tribes, and the conditions for the exchange of prisoners.

Upon the seizure of the imperial throne by Michael II in 820, the peace treaty is renewed.

The long peace has been a favorable time for an active internal policy for the further consolidation of the forming Bulgarian nation; removal of many internal threats for the stability and intensive building.

After the unsuccessful attempts of several Slavic chiefs to secede from Bulgaria, Omurtag has conclusively eliminated the autonomy of the Slavic tribes in the vast country.

He makes an administrative reform and divides the state into large provinces called comitati (singular comitat) whose governors are directly appointed by the Kanasubigi.

The comitati are further divided into smaller regions called zhupi (singular zhupa).

The area around the capital has a special status.

The Army has been integrated and becomes unified; it no longer relies on separate Slav infantry and Bulgarian cavalry.

At home, Omurtag has undertaken large scale construction, intended to both restore his capital Pliska, which had been destroyed by the imperial forces in 811, and to foster the development of a number of regional centers, palaces, and fortifications.

Omurtag pursues a policy of repression against Christians, in particular against the former prisoners of war settled by his father Krum in Bulgaria (mostly north of the Danube).

This policy may have been motivated in part by the invasion of 811 or with the beginning of Christian proselytizing by members of the substantial captive population.

In connection with these policies, Omurtag has disinherited his eldest son Enravota (Voin), who has shown himself sympathetic to Christianity.

Thomas unsuccessfully attacks Constantinople, while his fleet is destroyed by Michael's navy using Greek fire.

His army unable to breach the walls of the great city, Thomas is forced to retreat due to weather and a Bulgar army attacking him.

Michael, assisted by Omurtag and relying upon the defenses of Constantinople, succeeds in suppressing the revolt of Thomas the Slav at the end of 823, dealing Thomas a final defeat at Diabasis in Thrace.

Thomas and his supporters flee to Arcadiopolis, where they are blockaded by imperial troops.

After five months, Thomas is surrendered to Michael by his supporters and executed.

However, the revolt has so weakened the resources of the empire that it will be unable to resist later Arab onslaughts.

The episode suggests the tensions beneath the surface of society within the empire: the social malaise, the ethnic hostility, and the persisting discord created by Iconoclasm.