Background During the late 6th and early 7th centuries, the
Byzantine Empire was under frequent attack from all sides. The
Sassanid Empire was pressing from the east on
Syria,
Egypt, and
Anatolia.
Slavs and
Avars raided Thrace, Macedonia, Illyricum, and southern Greece and settled in the
Balkans. The
Lombards occupied northern
Italy, largely unopposed. In order to face the mounting pressure, in the more distant provinces of the West, recently regained by
Justinian I (r. 527–565), Emperor
Maurice (r. 582–602) combined supreme civil and military authority in the person of an
exarch, a
viceroy, forming the exarchates of
Ravenna and
Africa. These developments overturned the strict division of civil and military offices, which had been one of the cornerstones of the reforms of
Diocletian (r. 284–305). Said administrative restructurings also found a precedent in Justinian's broad reorganization in the western conquests, denoting combined powers to the newly established
Praetorian prefects of Africa (
Eparchos tes Afrikís) and
Italy (
Eparchos tes Italías) respectively. Justinian also endowed governors (
eparchs,
stratelates) of the eastern provinces plagued by brigandage and foreign invasions with military and administrative powers, formally abolishing the empire's
dioceses, Diocletian's main administrative structure, but more importantly, he had also created the exceptional combined military-civilian circumscription of the and following the norm, abolished the
Diocese of Egypt putting a (Greek:
stratelates) with combined authority at the head of each of its old provinces instead. The empire maintained this precedent structure until the 640s, when the eastern part of the Empire faced the
onslaught of the Muslim
Caliphate. The rapid Muslim conquest of Syria and Egypt and consequent Byzantine losses in manpower and territory meant that the Empire found itself struggling for survival. In order to respond to this unprecedented crisis, the Empire was drastically reorganized. As established by
Hellenistic political practice,
philosophies and
Orthodox doctrines, power had been concentrated in military leaders
strategoi who acted as
viceroys in their respective "
théma", being appointed by the emperor alone. Their main function around each was the collection of taxes from the different communities "
chora", "
komai" and from the different states "
proasteion" as well as the management of fast and flexible provincial armies. The remaining imperial territory in
Asia Minor was divided into four large themes, and although some elements of the earlier civil administration survived, they were subordinated to the governing general or .
Origins The origin and early nature of the themes has been heavily disputed amongst scholars. The very name is of uncertain etymology, but most scholars follow
Constantine Porphyrogennetos, who records that it originates from Greek ("placement"). The date of their creation is also uncertain. For most of the 20th century, the establishment of the themes was attributed to the Emperor
Heraclius (r. 610–641), during the
last of the
Byzantine–Sassanid Wars. Most notable amongst the supporters of this thesis was
George Ostrogorsky who based this opinion on an extract from the chronicle of
Theophanes the Confessor mentioning the arrival of Heraclius "in the lands of the themes" for the year 622. According to Ostrogorsky, this "shows that the process of establishing troops (themes) in specific areas of Asia Minor has already begun at this time." This view has been objected to by other historians however, and more recent scholarship dates their creation later, to the period from the 640s to the 660s, under
Constans II (r. 641–668). It has further been shown that, contrary to Ostrogorsky's conception of the being established from the outset as distinct, well-defined regions where a held joint military and civil authority, the term originally seems to have referred exclusively to the armies themselves, and only in the later 7th or early 8th centuries did it come to be transferred to the districts where these armies were encamped as well. Tied to the question of chronology is also the issue of a corresponding social and military transformation. The traditional view, championed by Ostrogorsky, holds that the establishment of the themes also meant the creation of a new type of army. In his view, instead of the old force, heavily reliant on foreign mercenaries, the new Byzantine army was based on native farmer-soldiers living on state-leased military estates (compare the organization of the Sasanian ). More recent scholars however have posited that the formation of the themes did not constitute a radical break with the past, but rather a logical extension of pre-existing, 6th-century trends, and that its direct social impact was minimal. The first four themes were those of the Armeniacs, Anatolics and Thracesians, and the Opsician theme. The
Armeniac Theme (, ), first mentioned in 667, was the successor of the Army of Armenia. It occupied the old areas of the
Pontus,
Armenia Minor and northern
Cappadocia, with its capital at
Amasea. The
Anatolic Theme (, ''''), first mentioned in 669, was the successor of the Army of the
East (, ). It covered southern central Asia Minor, and its capital was
Amorium. Together, these two themes formed the first tier of defence of Byzantine Anatolia, bordering Muslim Armenia and Syria respectively. The
Thracesian Theme (, ), first mentioned clearly as late as c. 740, was the successor of the Army of
Thrace, and covered the central western coast of Asia Minor (
Ionia,
Lydia and
Caria), with its capital most likely at
Chonae. The
Opsician Theme (, ), first mentioned in 680, was constituted from the imperial retinue (in
Latin ). It covered northwestern Asia Minor (
Bithynia,
Paphlagonia and parts of
Galatia), and was based at
Nicaea. Uniquely, its commander retained his title of (, "count"). In addition, the great naval division of the Carabisians or
Karabisianoi (, "people of the [ships]"), first mentioned in 680, was probably formed of the remains of the Army of the
Illyricum or, more likely, the old
quaestura exercitus. It never formed a theme proper, but occupied parts of the southern coast of Asia Minor and the Aegean Islands, with its seat most likely at
Samos. It provided the bulk of the
Byzantine navy facing the new Arab fleets, which after the
Battle of the Masts contested control of the Mediterranean with the Empire. In the event, the Carabisians would prove unsatisfactory in that role, and by 720 they had been disbanded in favour of a fully fledged naval theme, that of the
Cibyrrhaeots (,
Thema Kibyrrhaiotōn), which encompassed the southern coasts of Asia Minor and the
Aegean islands. The part of the region of
Thrace under Byzantine control was probably constituted as a theme at about 680, as a response to the
Bulgar threat, although for a time the command over Thrace appears to have been exercised by the Count of the
Opsikion. Successive campaigns by the emperors of the
Heraclian dynasty in Greece also led to the recovery of control of
Central Greece from
Slavic invaders, and to the establishment of the theme of
Hellas there between 687 and 695.
Sicily too was formed as a theme by the end of the 7th century, but the imperial possessions in mainland
Italy remained under the exarch of Ravenna or the local
doukes, as did
Byzantine Africa until the fall of
Carthage in 698. At the same time,
Crete and the imperial exclave of
Cherson in the
Crimea formed independent
archontiai. Thus, by the turning of the century, the themes had become the dominant feature of imperial administration. Their large size and power however made their generals prone to revolt, as had been evidenced in the turbulent period 695–715, and would again during the great revolt of
Artabasdos in 741–742. The suppression of Artabasdos' revolt heralded the first significant changes in the Anatolian themes: the over-mighty
Opsikion was broken up with the creation of two new themes, the
Bucellarian Theme and the
Optimates, while the role of imperial guard was assumed by a new type of professional force, the imperial
tagmata.
Height of the theme system, 780s–950s Despite the prominence of the themes, it was some time before they became the basic unit of the imperial administrative system. Although they had become associated with specific regions by the early 8th century, it took until the end of the 8th century for the civil fiscal administration to begin being organized around them, instead of following the old provincial system. This process, resulting in unified control over both military and civil affairs of each theme by its
strategos, was complete by the mid-9th century, and is the "classical" thematic model mentioned in such works as the
Klētorologion and the
De Administrando Imperio. At the same time, the need to protect the Anatolian heartland of Byzantium from the Arab raids led to the creation, in the later 8th and early 9th centuries, of a series of small frontier districts, the
kleisourai or
kleisourarchiai ("defiles, enclosures"). The term was previously used to signify strategically important, fortified mountain passages, and was now expanded to entire districts which formed separate commands under a
kleisourarchēs, tasked with guerrilla warfare and locally countering small to mid-scale incursions and raids. Gradually, most of these were elevated to full themes.
Decline of the system, 960s–1070s With the beginning of the Byzantine offensives in the East and the Balkans in the 10th century, especially under the warrior-emperors
Nikephoros II (r. 963–969),
John I Tzimiskes (r. 969–976) and
Basil II (r. 976–1025), newly gained territories were also incorporated into themes, although these were generally smaller than the original themes established in the 7th and 8th centuries. At this time, a new class of themes, the so-called "minor" () or "Armenian" themes () appear, which Byzantine sources clearly differentiate from the traditional "great" or "Roman" themes (). Most consisted merely of a fortress and its surrounding territory, with a junior
stratēgos (called by the Arabs and by the Armenians) as a commander and about 1,000 men, chiefly infantry, as their garrison. As their name reveals, they were mostly populated by
Armenians, either indigenous or settled there by the Byzantine authorities. One of their peculiarities was the extremely large number of officers (the theme of
Charpezikion alone counted 22 senior and 47 junior
tourmarchai). While well suited for defence, the "Armenian" themes were incapable of responding to major invasions or undertake sustained offensive campaigns on their own. Thus, from the 960s, more and more professional regiments, both from the old
tagmata and newly raised formations, were stationed along the border. To command them as well as coordinate the forces of the small frontier themes, a number of large regional commands ("" or ""), under a
doux or
katepano, were set up. In the East, the three original such commands, set up by John Tzimiskes, were those of the
doukes of
Antioch,
Chaldia and
Mesopotamia. As Byzantium expanded into
Greater Armenia in the early 11th century, these were complemented or replaced by the commands of
Iberia,
Vaspurakan,
Edessa and
Ani. In the same vein, the "Armenian" themes seem to have been placed under a single
strategos in the mid-11th century.
Change and decline: 11th–12th centuries The
Komnenian era saw a brief restoration of the empire's fortunes as the force now known as the '
Komnenian army' was established by
Alexios I Komnenos, marking a decisive break with the thematic system. The new army was highly centralized in the person of the emperor and the ruling dynasty, and provided an element of stability which characterized the Komnenian restoration. It was noticeably more reliant on mercenaries such as the
Varangian guard than the previous army, reducing the importance of the themes. The
strategoi increasingly lost power as the empire centralized. The emperors often appointed relatives to the governorships, reducing their autonomous character and solidifying centralized imperial administration. The
Komnenian restoration required a new system to manage the severely weakened themes of
Anatolia due to the catastrophe of
Manzikert. The themes followed the Kommenian era trend of greater imperial centralization with the governors being members of the imperial family, owing their allegiance solely to the emperor. This eroded the old independent character of the once large Anatolian themes. The new military governors (called
Doux or
Katepanos indiscriminately) assumed strongly centralized roles on the emperor's behalf so that the influx of landed
pronoia foreigners in military service could be regulated and counteracted in cases of uprising. The governorships were specifically reserved for relatives of the Komnenian family alone and though efficient emergency measures, it successfully turned the empire into a dependency on foreign mercenaries, yielding the mass of native Greeks and making it unprecedentedly subordinate to the will of its European counterparts. Each Theme was overseen by a
Katepanos or
Doux, whose authorities was both military and civil, subdivided into
Katepanakias encompassing the old
Tourmas, now each ruled by a
Praktor instead of a
Tourmarches fulfilling the same civic and military roles now widely in the hands of
pronoiars. The pronoiars became the bulk of the imperial tagmata's reserves, slowly taking their place side by side with the totally lawless landed monasteries and the
dynatoi, who after Alexios's tax reforms could formalize the various illegally acquired towns and communes as long as they could secure the full taxation of their new domains by the fisc, a process worse fueled by the extensive
chrysobulas of different institutions granted by the monarch. The
Byzantine army of the Komnenian era never managed to field the manpower of the themes in their heyday, and the new system proved more expensive to maintain in the long run. It also relied on a succession of strong soldier-emperors to be effective. With the death of
Manuel I Komnenos in 1180, a new period of decline set in.
Late Byzantine themata The neglect under the
Angeloi dynasty and the weakening of central authority made the themes increasingly irrelevant in the late 12th century. Regional civil authorities such as the 'despotates' grew in power as central authority collapsed, rendering the themes moribund by the onset of the
Palaiologos dynasty's rule. The now irrelevant micro provinces under imperial control were organized directly into
katepanakias or
kephalatikion each also ruled by a
Katepan or
Kephale with military and civic powers centered around forts and major passes, relegating all minor tasks to deputies. ==Organization==