Byzantine-Muslim War of 803-09

The commercial empire of the Turkic Khazars, centered in the southeastern section of modern European Russia, adopts Judaism in about 740 and continues its alliance with Constantinople against the Muslim Arabs.

The East Roman Empire is beset from within by Iconoclast controversy and from without by the Arab Caliphate to the east and south and the newly formed Bulgarian Empire to the north.

The rapid expansion of Islam from the Middle East to Spain in the seventh and eighth centuries brings a significant portion of the Jewish people under Muslim rule.

Jews, tolerated by Muslims as People of the Book, with a common ancestor in Abraham, regain religious autonomy and, as long as they pay tribute to the rulers, see to the affairs of their communities.

The Fragmentation of the Arab Caliphate and the Rise of Independent Muslim States

Throughout this period, the Arab Caliphate, predominantly ruled by the Umayyad dynasty, is fractured by a series of civil wars, one of which leads to the split of Islam into three major branches:

• Sunnites,
• Kharijites, and
• Shi'ites.

This internal strife ultimately shatters unified Islamic rule. In 750 CE, the Abbasids overthrow the Umayyads, seizing control of the Caliphate. However, a cadet branch of the Umayyads escapes to Muslim Spain, where they establish the Emirate of Córdoba, marking the beginning of an independent Islamic state in Al-Andalus.

Elsewhere, other independent Muslim states emerge, including:

• Idrisid Morocco, and
• Aghlabid Ifriqiya (modern Tunisia, eastern Algeria, and western Libya).

These developments mark the transition from a unified Arab Empire to a diverse Islamic world, ruled by multiple, competing dynasties.

In 711 CE, Muslim Arab and Berber forces launch an invasion of Visigothic Spain from North Africa, swiftly defeating the Visigothic kingdom. Within a few years, they conquer nearly all of the Iberian Peninsula, except for the northernmost regions, where Christian resistance endures.

Their expansion also extends into Septimania in southern Gaul, further consolidating Muslim rule in Western Europeand marking the beginning of Al-Andalus, a new Islamic domain in Iberia.

Nikephoros’s rule is endangered by Bardanes Tourkos, one of his ablest generals, who revolts and receives support from other commanders, notably the later emperors Leo V the Armenian and Michael II the Amorian in 803.

Nikephoros gains over the latter two, however, and by inducing the rebel army to disperse achieves the submission of Bardanes, who is relegated to a monastery and blinded there.

A conspiracy headed by the patrician Arsaber has a similar result.

The deposition of Empress Irene and subsequent accession of Nikephoros I signals a more violent phase in the long history of the Arab–Byzantine Wars.

Following a series of destructive annual raids across Asia Minor by the Caliphate, Irene seems to have secured a truce with Harun al-Rashid in 798 in exchange for the annual payment of tribute, repeating the terms agreed for a three-year truce following Harun's first large-scale campaign in 782.

Nikephoros, on the other hand, is more warlike and determined to refill the imperial treasury by, among other measures, ceasing the tribute.

Harun retaliates at once, launching a raid under his son al-Qasim.

Nikephoros cannot respond to this facing the ultimately unsuccessful revolt of the Asian army under Bardanes Tourkos.

After disposing of Bardanes, Nikephoros assembles his army and marches out himself to meet a second, larger invasion under the Caliph himself.

After Harun raids the frontier region, the two armies confront each other for two months in central Asia Minor, but it does not come to a battle; Nikephoros and Harun exchange etter until the Emperor arranges for a withdrawal and a truce for the remainder of the year in exchange for a one-off payment of tribute.

Nikephoros embarks on a general reorganization of the Empire, creating new themes in the Balkans and strengthening the frontiers.

Needing large sums to increase his military forces, he sets himself with great energy to increase the Empire's revenue, reimposing the taxes that Irene had remitted, and instituting other reforms that provide some insight into the financial administration of the empire during the early ninth century.

By his rigorous tax imposts he alienates the favor of his subjects, and especially of the clergy, whom he otherwise seeks to control firmly.

Although he appoints an iconodule, Nikephoros, as patriarch, Emperor Nikephoros is portrayed as a villain by ecclesiastical historians like Theophanes the Confessor.

He crowns his son Staurakios co-emperor in December 803.

In the same year, Nikephoros concludes a treaty, called the "Pax Nicephori", with Charles I of the Franks, but refuses to recognize the latter's imperial dignity.

Nikephoros I, on becoming emperor after Irene was deposed, had refused to pay tribute to Harun, saying that Irene should have been receiving the tribute the whole time.

News of this angers Harun, who writes a message on the back of the Roman emperor's letter and says,

"In the name of God the most merciful, From Amir al-Mu'minin Harun al-Rashid, commander of the faithful, to Nikephoros, dog of the Romans.

Thou shalt not hear, thou shalt behold my reply".

Harun’s capital at Baghdad, renowned for the magnificence of his court, has become a vigorous center of commercial activity.

The administration of the 'Abbasid empire has for more than sixteen years been mainly the responsibility of members of the priestly Barmakid family, who have provided the money for the luxury and extravagance of Harun al Rashid's court.

Ja'far ibn Yahya, who had inherited the position of vizier to the caliph from his father, Yahya, has a reputation as a patron of the sciences, and has done much to introduce Greek science into Baghdad, attracting scholars from the nearby Academy of Gundishapur to help translate Persian works into Arabic (the so-called "Translation Movement").

He is also credited with persuading the caliph to open a paper mill in Baghdad, the secret of papermaking having been obtained in 751 from Chinese prisoners at the Battle of Talas in present day Kyrgyzstan.

Moreover, Ja'far has become Harun's special friend, so that gossip speaks of a homosexual relationship.

Gossip also alleges that Harun had arranged that Ja'far should secretly marry his sister 'Abbasah, on condition that he did not consummate the marriage, but Ja'far fell in love with her, and she had a child.

Whether in anger at this or not, Harun has the thirty-six-year-old Ja'far executed on January 29, 803, and parts of his body displayed on the bridges of Baghdad.

The other members of the family are imprisoned and their goods confiscated.

Diverse interests within the 'Abbasid empire are being attracted to two opposing poles.

On the one side are the “secretaries’”, or civil servants, many Persians, and many men from the eastern provinces; on the other side are the religious scholars ('ulama'), many Arabs, and many from the western provinces.

Since the Barmakids favor the first group of interests and the new vizier, al-Fadl ibn ar-Rabi', favors the second, it is likely that this political cleavage is involved in the change of ministry.

Harun dispatches another raid under his general Ibrahim ibn Jibril in August 804.

The Arabs cross into Asia Minor through the Cilician Gates and raid freely.

Nikephoros sets out to meet them, but is forced to return before he can do so, due to some unspecified event at his back.

On his march home, however, the Arabs launch a surprise attack at Krasos in Phrygia and defeat his army.

According to al-Tabari, the imperial army lost forty thousand seven hundred men and four thousand pack animals, while the Emperor himself was wounded three times.

The Byzantine chronicler Theophanes the Confessor confirms that the imperial army lost many men and that Nikephoros was almost killed himself; saved only by the bravery of his officers.

As Harun is preoccupied with trouble in Khorasan, the caliph now accepts tribute and made peace.

An exchange of prisoners is also arranged and takes place during the winter at the two empires' border, on the Lamos river in Cilicia; some thirty-seven hundred Muslims are exchanged for the imperial troops taken captive in the previous years.

The military commander Leo the Armenian and his comrade-in-arms Michael the Amorian had at first supported Bardanes Tourkos when he and Nikephoros I were fighting over the imperial throne in 803, but later desert him and join the cause of Nicephoros.

Leo, having distinguished himself as a general under Nikephoros, becomes strategos of the Anatolic theme.