First themes: 7th–8th centuries
The massive Arab invasions forced major changes in the Eastern Roman military. At some point in the mid-7th century, probably in the late 630s and 640s, the Empire's field armies were withdrawn to Anatolia, the last major contiguous territory remaining to the Empire. The armies were assigned to the districts that became known as the themes.
For 500 years the Eastern Roman heartland of Anatolia was ground zero for endless invasions by Arab Muslim forces and counter attacks by Roman troops.
At the heart of the battle against Islam was the Anatolic Theme, more properly known as the Theme of the Anatolics, was an Eastern Roman theme (a military-civilian province) in central Asia Minor.
From its establishment, it was the largest and senior-most of the themes, and its military governors (stratēgoi) were powerful individuals, several of them rising to the imperial throne or launching failed rebellions to capture it.
The theme and its army played an important role in the Arab–Byzantine wars of the 7th–10th centuries, after which it enjoyed a period of relative peace that lasted until its conquest by the Seljuk Turks in the late 1070s.
Initially, the Anatolic Theme included the western and southern shores of Asia Minor as well, but by c. 720 they were split off to form the Thracesian and Cibyrrhaeot themes.
Under Theophilos (r. 829–842), its eastern and south-eastern portions, facing the Arab frontier zone and including the forts that guarded the northern entrance to the Cilician Gates.
According to the 10th-century Arab geographers Qudama ibn Ja'far and Ibn al-Faqih, the Anatolic Theme, "the largest of the provinces of the Romans", fielded 15,000 men, and contained 34 fortresses.
It and its military governor, or stratēgos, first attested in 690, ranked first in precedence among the theme governors. As such, the "stratēgos of the Anatolics" was one of the highest in the Empire, and one of the few posts from which eunuchs were specifically barred.
The holders of the post received an annual salary of 40 pounds of gold, and are attested as holding the senior court ranks of patrikios, anthypatos, and prōtospatharios. In addition, they were the only ones to be appointed to the exceptional post of monostrategos ("single-general"), overall commander of the Asian land themes.
The exact date of the theme's establishment is unknown. Along with the other original themes, it was created sometime after the 640s as a military encampment area for the remnants of the old field armies of the East Roman army, which were withdrawn to Asia Minor in the face of the Muslim conquests.
The Anatolic Theme was settled and took its name from the Army of the East. The theme is attested for the first time in 669, while the army itself is mentioned, as the exercitus Orientalis, as late as an iussio of Justinian II in 687.
The thematic capital, Amorium, was also a frequent target of the Arabs. It was attacked already in 644, captured in 646, and briefly occupied in 669. The Arabs reached it again in 708 and besieged it without success in 716, during their march on Constantinople.
The tide of the Arab attacks ebbed in the 740s, after the Byzantine victory at the Battle of Akroinon and the turmoil of Muslim civil wars. Under Emperor Constantine V (r. 741–775), the Anatolics spearheaded the Roman campaigns into Arab-held territory. This in turn provoked the reaction of the Abbasid Caliphate, which in the quarter-century after 780 launched repeated invasions of Roman Asia Minor. Thus the Anatolics suffered a heavy defeat at Kopidnadon in 788, and Amorium was threatened again in 797.
In the early years of the 9th century, Cappadocia was the focus of Arab attacks, which culminated in the great invasion of 806 led by Caliph Harun al-Rashid (r. 786–809) himself, which took Heraclea Cybistra and several other forts.
The late antique urban fabric suffered considerably from the Arab attacks and the concomitant decline of urbanization, but most of the cities in the interior of the theme, i.e. in Phrygia and Pisidia, survived, albeit in a reduced form. The cities of eastern Cappadocia which bordered the Caliphate were practically destroyed.
With new Roman settlers moving east Arab raids were often absorbed there, and seldom reached the Anatolic Theme's territory.
Apart from the Caliph's great invasion against Amorium in 838, some attacks penetrated into the Anatolics' territory are reported for the year 878, when the thematic troops successfully defended Mistheia, and again in 888, 894 and 897, always in the southeastern portion of the theme around Iconium.
The first Turkish attack on the theme is recorded in 1069, when the Turks attacked Iconium. Most of the province was overrun by the Turks after the Battle of Manzikert in 1071, with Iconium becoming the seat of the Seljuk Sultanate of Rum in the 12th century.
The last appearance of the Anatolic Theme in the historical sources is in 1077, when its stratēgos, Nikephoros Botaneiates, proclaimed himself emperor (Nikephoros III, r. 1078–1081).
The Romans managed to recover some of the western and northern portions of the theme in the subsequent decades under the Komnenian emperors, but the Anatolic Theme was never reconstituted.
Because it faced the forces of the Caliphate during its first centuries of existence the Anatolic Theme was the most powerful and most prestigious of the themes.
Its very power, however, also meant that it was a potential threat to the Emperors.
As early as 669 the thematic army revolted and forced Constantine IV (r. 668–685) to re-install his brothers, Heraclius and Tiberius as his co-emperors, while in 695 a former stratēgos, Leontios (r. 695–698), usurped the throne from Justinian II (r. 685–695, 705–711), and in 717 the then stratēgos, Leo the Isaurian, became emperor (Leo III, r. 717–741) after deposing Theodosios III (r. 715–717).
The Anatolic Theme served as the base for several bids for the throne in later centuries as well: the failed revolt of Bardanes Tourkos in 803 was followed by the successful proclamation of Leo V the Armenian (r. 813–820) by the Anatolic troops in 813, and the large-scale rebellion of Thomas the Slav in 820–823.
In the 10th century, however, the theme appears on the sidelines of the rebellions of the period. The next and last rebellion by a stratēgos of the Anatolics was that of Nikephoros Xiphias in 1022, against Basil II (r. 976–1025).