The Empire's field armies are withdrawn at some point in the mid-seventh century, probably in the late 630s, to Anatolia, the last major contiguous territory remaining to the Empire, and assigned to the districts that will become known as the themes.

Heraclius creates a buffer zone or no man's land in the heartland of Asia Minor.

In the mountainous terrain of Anatolia, the imperial forces develop a system of defensive guerrilla warfare.

The strategy is known as ‘shadowing warfare’, as it avoids battle with major Muslim invasions and instead attacks raiding parties on their return when they are laden with booty, captured livestock or prisoners.

Maslama ibn Abd al-Malik is the son of the Umayyad caliph Abd al-Malik ibn Marwan (reigned 685–705) and half-brother of the caliphs al-Walid I (r. 705–715), Sulayman (r. 715–717), Yazid II (r. 720–724) and Hisham (r. 724–743).

Maslama himself had been excluded from the line of succession as his mother was an enslaved woman.

He is first mentioned as leading, along with his nephew al-'Abbas ibn al-Walid, the annual summer campaign (ṣawā'if) against the Empire in 705.

His first major expedition is the 707–708 campaign against the imperial city of Tyana in southeastern Asia Minor, which had been launched in retaliation for the defeat and death of the distinguished general Maimun the Mardaite the year before.

The siege lasts through winter and the Arab army faces great hardship, but after the Arabs defeat an imperial relief force in spring 708, the city surrenders.

A few months later, in the summer, …

…Tyana and …

The other two forces achieve little of consequence in the already repeatedly devastated area, but Abbas meets with more success: he forces the town of Tyana to capitulate and razed it, and met and defeats the imperial army under the emperor Theophilos in a minor skirmish.

Caliph al-Ma'mun, having brought the ‘Abbasid caliphate to its greatest heights, had kept up the pressure on the Empire in 832, with his army capturing the strategically important fortress of Loulon, and in late 832 the Caliph had begun gathering a huge army and announced that he intends to conquer and colonize Anatolia step by step, and finally subjugate the Empire by capturing Constantinople itself.

Consequently, on May 833, Abbas with the advance force marches into imperial territory and begins creating a military base at the site of Tyana.

The site has been fortified and awaits the arrival of the Caliph's army, which in early July crosses into Anatolia.

At his juncture, however, luck intervenes for Constantinople, as Ma'mun falls ill and dies on October 10, although some modern scholars speculate that his death may have been the result of a coup.

Although Abbas is Ma'mun's only son, the Caliph apparently had named his brother Abu Ishak al-Mu’tasim, a younger son of the late Harun ar-Rashid, as his heir shortly before his death.

Abbas swiftly swears allegiance to Mu'tasim, but this turn of events is not popular among the assembled army, which tries to proclaim Abbas caliph.

Abbas refuses, and manages to assuage the troops' anger.

Nevertheless, Mu'tasim's hold on the throne is still shaky, and he abandons Ma'mun's campaign; the new base at Tyana is razed, and the army returns to the Caliphate.

Umar strikes again in the summer of 863, joining forces with the Abbasid general Ja'far ibn Dinar al-Khayyat (probably the governor of Tarsus) for a successful raid into Cappadocia.

The Arabs cross he Cilician Gates into imperial territory, plundering as they go, until they reach a place near Tyana.

Here, the Tarsian army returns home, but Umar obtains Ja'far's leave to press on into Asia Minor.

Umar's forces represen the bulk of his emirate's strength, but their size is unknown: the contemporary Muslim historian Ya'qubi claims that Umar had eight thousand men at his disposal, while the Byzantine historians Genesius and Theophanes Continuatus inflate the numbers of the Arab army to forty thousand men.

The Byzantinist John Haldon considers the former number to be closer to reality, and estimates the size of the combined Arab force at fifteen to twenty thousand men.

It is likely that a Paulician contingent under Karbeas was present as well.