Bucellarian Theme

The caliphal forces invade imperial territory in 797, advancing to Ancyra.

Nikephoros launches the first raid by the Empire for two decades into the Arab frontier district (thughur) in Cilicia in summer 805.

The imperial army raids and takes prisoners as it goes, even capturing the major Abbasid stronghold of Tarsus.

At the same time, …

…another imperial force raids the Upper Mesopotamian thughur and unsuccessfully besieges the fortress of Melitene, while …

…a Constantinople-instigated rebellion against the local Arab garrison begins in Cyprus.

Harun responds to the empire’s raids with a massive invasion in 806, leading an army with more than one hundred and thirty-five thousand men across Anatolia's Taurus Mountains and seizing the city of Heraclea Cybistra (Eregli).

The Muslims score victories on land and sea, taking …

…Tyana and …

…Ancyra in 806.

Nikephoros, unable to counter the Muslim numbers, agrees to make peace on condition of paying fifty thousand nomismata immediately and a yearly tribute of thirty thousand nomismata.

Al-Mu’tasim, determined to crush the Greeks, leads the largest army yet assembled under one caliph—composed of Arab warriors, Turkish guards, and enslaved men—into Anatolia, where he defeats Theophilus's forces in July 838 at the bloody Battle of Dazimon (now Dazmana, Turkey) on the Halys River.

Al-Mu'tasim thus becomes the first caliph to employ the Turkish mercenaries who will later come to dominate the 'Abbasid dynasty.

In the aftermath of this defeat, and with rumors circulating in Constantinople of his death, Theophilos's position is precarious.

He abandons the campaign and withdraws to Dorylaion, whence he soon departs for the imperial capital.

Ancyra itself is left abandoned, and plundered by the Arab army on 27 July, after which …

…the united Abbasid army marches unopposed to Amorion, besieging the fortress for two weeks.

Just before its capture by the Arabs, fighting breaks out between Jews and Christians.

Included in the conflict is a Judaizing Christian sect that keeps Biblical Law (except circumcision) and allows both men and women to serve as spiritual leaders.

Rumors are spread that the late Emperor Michael II had come from this sect.

Out of its entire population of some seventy thousand, only about half survive the brutal sack, to be sold as slaves.

The fall of the city is to be one of the heaviest blows suffered by the Empire in the entire ninth century, both in material and symbolic terms.

Luckily for the Empire, news of a rebellion in the Caliphate forces al-Mu'tasim to withdraw soon after.

Tragic though they are for the Empire at the time, the defeat at Anzen and the subsequent sack of Amorion are militarily of no long-term importance to the Empire, since the Abbasids fail to follow up on their success.

They do, however, play a crucial role in discrediting iconoclasm, which has always relied on military success to maintain its validity.

Immediately after the sack, rumors reach the caliph that Theophilos was advancing to attack him.

Mu'tasim sets out with his army a day's march along the road in the direction of Dorylaion, but encounters no sign of an imperial attack.

According to al-Tabari, Mu'tasim now pondered extending his campaign to attack Constantinople, when news reached him of a rebellion headed by his nephew, al-Abbas ibn al-Ma'mun.

Mu'tasim is forced to cut short his campaign and return quickly to his realm, leaving intact the fortresses around Amorium as well as Theophilos and his army in Dorylaion.

Taking the direct route from Amorium to the Cilician Gates, both the caliph's army and its prisoners suffer in the march through the arid countryside of central Anatolia.

Some captives are so exhausted that they cannot move and are executed, whereupon others find the opportunity to escape.

In retaliation, Mu'tasim, after separating the most prominent among them, executes the rest, some six thousand in number.