The themes or (, ,
singular: , ) were the main military and
administrative divisions
Administrative divisions (also administrative units, administrative regions, subnational entities, or constituent states, as well as many similar generic terms) are geographical areas into which a particular independent sovereign state is divi ...
of the middle
Byzantine Empire
The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived History of the Roman Empire, the events that caused the ...
. They were established in the mid-7th century in the aftermath of the
Slavic migrations to Southeastern Europe
Early Slavs began mass migrating to Southeastern Europe between the first half of the 6th and 7th century in the Early Middle Ages. The rapid demographic spread of the Slavs was followed by a population exchange, mixing and language shift to and ...
and
Muslim conquests The Muslim conquests, Muslim invasions, Islamic conquests, including Arab conquests, Arab Islamic conquests, also Iranian Muslim conquests, Turkic Muslim conquests etc.
*Early Muslim conquests
** Ridda Wars
**Muslim conquest of Persia
*** Muslim co ...
of parts of Byzantine territory, and replaced the earlier
provincial system established by
Diocletian
Diocletian ( ; ; ; 242/245 – 311/312), nicknamed Jovius, was Roman emperor from 284 until his abdication in 305. He was born Diocles to a family of low status in the Roman province of Dalmatia (Roman province), Dalmatia. As with other Illyri ...
and
Constantine the Great
Constantine I (27 February 27222 May 337), also known as Constantine the Great, was a Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a Constantine the Great and Christianity, pivotal ro ...
. In their origin, the first themes were created from the areas of encampment of the field armies of the
East Roman army, and their names corresponded to the military units that had existed in those areas. The theme system reached its apogee in the 9th and 10th centuries, as older themes were split up and the conquest of territory resulted in the creation of new ones. The original theme system underwent significant changes in the 11th and 12th centuries, but the term remained in use as a provincial and financial circumscription until the very end of the Empire.
History
Background
During the late 6th and early 7th centuries, the
Byzantine Empire
The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived History of the Roman Empire, the events that caused the ...
was under frequent attack from all sides. The
Sassanid Empire
The Sasanian Empire (), officially Eranshahr ( , "Empire of the Iranians"), was an Iranian empire that was founded and ruled by the House of Sasan from 224 to 651. Enduring for over four centuries, the length of the Sasanian dynasty's reign ...
was pressing from the east on
Syria
Syria, officially the Syrian Arab Republic, is a country in West Asia located in the Eastern Mediterranean and the Levant. It borders the Mediterranean Sea to the west, Turkey to Syria–Turkey border, the north, Iraq to Iraq–Syria border, t ...
,
Egypt
Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...
, and
Anatolia
Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...
.
Slavs
The Slavs or Slavic people are groups of people who speak Slavic languages. Slavs are geographically distributed throughout the northern parts of Eurasia; they predominantly inhabit Central Europe, Eastern Europe, Southeastern Europe, and ...
and
Avars raided Thrace, Macedonia, Illyricum, and southern Greece and settled in the
Balkans
The Balkans ( , ), corresponding partially with the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throug ...
. The
Lombards
The Lombards () or Longobards () were a Germanic peoples, Germanic people who conquered most of the Italian Peninsula between 568 and 774.
The medieval Lombard historian Paul the Deacon wrote in the ''History of the Lombards'' (written betwee ...
occupied northern
Italy
Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...
, largely unopposed. In order to face the mounting pressure, in the more distant provinces of the West, recently regained by
Justinian I
Justinian I (, ; 48214 November 565), also known as Justinian the Great, was Roman emperor from 527 to 565.
His reign was marked by the ambitious but only partly realized ''renovatio imperii'', or "restoration of the Empire". This ambition was ...
(r. 527–565), Emperor
Maurice (r. 582–602) combined supreme civil and military authority in the person of an ''
exarch
An exarch (;
from Ancient Greek ἔξαρχος ''exarchos'') was the holder of any of various historical offices, some of them being political or military and others being ecclesiastical.
In the late Roman Empire and early Byzantine Empire, ...
'', a
viceroy
A viceroy () is an official who reigns over a polity in the name of and as the representative of the monarch of the territory.
The term derives from the Latin prefix ''vice-'', meaning "in the place of" and the Anglo-Norman ''roy'' (Old Frenc ...
, forming the exarchates of
Ravenna
Ravenna ( ; , also ; ) is the capital city of the Province of Ravenna, in the Emilia-Romagna region of Northern Italy. It was the capital city of the Western Roman Empire during the 5th century until its Fall of Rome, collapse in 476, after which ...
and
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...
. These developments overturned the strict division of civil and military offices, which had been one of the cornerstones of the reforms of
Diocletian
Diocletian ( ; ; ; 242/245 – 311/312), nicknamed Jovius, was Roman emperor from 284 until his abdication in 305. He was born Diocles to a family of low status in the Roman province of Dalmatia (Roman province), Dalmatia. As with other Illyri ...
(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
Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...
(''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
In Ecclesiastical polity, church governance, a diocese or bishopric is the ecclesiastical district under the jurisdiction of a bishop.
History
In the later organization of the Roman Empire, the increasingly subdivided Roman province, prov ...
, 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
The Diocese of Egypt (; ) was a diocese of the later Roman Empire (from 395 the Eastern Roman Empire), incorporating the provinces of Egypt and Cyrenaica. Its capital was at Alexandria, and its governor had the unique title of '' praefectus au ...
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
A caliphate ( ) is an institution or public office under the leadership of an Islamic steward with Khalifa, the title of caliph (; , ), a person considered a political–religious successor to the Islamic prophet Muhammad and a leader of ...
. 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
''Strategos'' (), also known by its Latinized form ''strategus'', is a Greek term to mean 'military general'. In the Hellenistic world and in the Byzantine Empire, the term was also used to describe a military governor. In the modern Hellenic ...
'' who acted as
viceroy
A viceroy () is an official who reigns over a polity in the name of and as the representative of the monarch of the territory.
The term derives from the Latin prefix ''vice-'', meaning "in the place of" and the Anglo-Norman ''roy'' (Old Frenc ...
s 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
Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...
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
Heraclius (; 11 February 641) was Byzantine emperor from 610 to 641. His rise to power began in 608, when he and his father, Heraclius the Elder, the Exarch of Africa, led a revolt against the unpopular emperor Phocas.
Heraclius's reign was ...
(r. 610–641), during the
last
A last is a mechanical form shaped like a human foot. It is used by shoemakers and cordwainers in the manufacture and repair of shoes. Lasts come in many styles and sizes, depending on the exact job they are designed for. Common variations ...
of the
Byzantine–Sassanid Wars. Most notable amongst the supporters of this thesis was
George Ostrogorsky
George Alexandrovich Ostrogorsky (; sr-Cyrl-Latn, Георгије Александрович Острогорски, Georgije Aleksandrovič Ostrogorski; 19 January 1902 – 24 October 1976) was a Russian-born Yugoslavian historian and Byzantin ...
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
Constans II (; 7 November 630 – 15 July 668), also called "the Bearded" (), was the Byzantine emperor from 641 to 668. Constans was the last attested emperor to serve as Roman consul, consul, in 642, although the office continued to exist unti ...
(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.
First themes: 640s–770s

What is clear is that 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, and assigned to the districts that became known as the themes. Territorially, each of the new themes encompassed several of the older provinces, and with a few exceptions, seems to have followed the old provincial boundaries. 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
Lesser Armenia (; ; ), also known as Armenia Minor and Armenia Inferior, comprised the Armenian-populated regions primarily to the west and northwest of the ancient Kingdom of Armenia (also known as Kingdom of Greater Armenia), on the western sid ...
and northern
Cappadocia
Cappadocia (; , from ) is a historical region in Central Anatolia region, Turkey. It is largely in the provinces of Nevşehir, Kayseri, Aksaray, Kırşehir, Sivas and Niğde. Today, the touristic Cappadocia Region is located in Nevşehir ...
, with its capital at
Amasea. The
Anatolic Theme (, '), first mentioned in 669, was the successor of the Army of the
East
East is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth.
Etymology
As in other languages, the word is formed from the fact that ea ...
(, ). It covered southern central Asia Minor, and its capital was
Amorium
Amorium, also known as Amorion (), was a city in Phrygia, Asia Minor which was founded in the Hellenistic period, flourished under the Byzantine Empire, and declined after the Sack of Amorium, Arab sack of 838. It was situated on the Byzantine m ...
. Together, these two themes formed the first tier of defence of Byzantine Anatolia, bordering Muslim Armenia and Syria respectively. The
Thracesian Theme
The Thracesian Theme (, ''Thrakēsion thema''), more properly known as the Theme of the Thracesians (, ''thema Thrakēsiōn'', often simply , ''Thrakēsioi''), was a Byzantine theme (a military-civilian province) in western Asia Minor (modern Tu ...
(, ), first mentioned clearly as late as c. 740, was the successor of the Army of
Thrace
Thrace (, ; ; ; ) is a geographical and historical region in Southeast Europe roughly corresponding to the province of Thrace in the Roman Empire. Bounded by the Balkan Mountains to the north, the Aegean Sea to the south, and the Black Se ...
, and covered the central western coast of Asia Minor (
Ionia
Ionia ( ) was an ancient region encompassing the central part of the western coast of Anatolia. It consisted of the northernmost territories of the Ionian League of Greek settlements. Never a unified state, it was named after the Ionians who ...
,
Lydia
Lydia (; ) was an Iron Age Monarchy, kingdom situated in western Anatolia, in modern-day Turkey. Later, it became an important province of the Achaemenid Empire and then the Roman Empire. Its capital was Sardis.
At some point before 800 BC, ...
and
Caria
Caria (; from Greek language, Greek: Καρία, ''Karia''; ) was a region of western Anatolia extending along the coast from mid-Ionia (Mycale) south to Lycia and east to Phrygia. The Carians were described by Herodotus as being Anatolian main ...
), with its capital most likely at
Chonae. The
Opsician Theme (, ), first mentioned in 680, was constituted from the imperial retinue (in
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
). It covered northwestern Asia Minor (
Bithynia
Bithynia (; ) was an ancient region, kingdom and Roman province in the northwest of Asia Minor (present-day Turkey), adjoining the Sea of Marmara, the Bosporus, and the Black Sea. It bordered Mysia to the southwest, Paphlagonia to the northeast a ...
,
Paphlagonia
Paphlagonia (; , modern translit. ''Paflagonía''; ) was an ancient region on the Black Sea coast of north-central Anatolia, situated between Bithynia to the west and Pontus (region), Pontus to the east, and separated from Phrygia (later, Galatia ...
and parts of
Galatia
Galatia (; , ''Galatía'') was an ancient area in the highlands of central Anatolia, roughly corresponding to the provinces of Ankara and Eskişehir in modern Turkey. Galatia was named after the Gauls from Thrace (cf. Tylis), who settled here ...
), and was based at
Nicaea
Nicaea (also spelled Nicæa or Nicea, ; ), also known as Nikaia (, Attic: , Koine: ), was an ancient Greek city in the north-western Anatolian region of Bithynia. It was the site of the First and Second Councils of Nicaea (the first and seve ...
. Uniquely, its commander retained his title of (, "count").
In addition, the great naval division of the Carabisians or ''
Karabisianoi'' (, "people of the
hips
In vertebrate anatomy, the hip, or coxaLatin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) (: ''coxae'') in medical terminology, refers to either an anatomical region or a joint ...
), first mentioned in 680, was probably formed of the remains of the Army of the
Illyricum or, more likely, the old ''
quaestura exercitus
The was an administrative district of the Byzantine Empire, Eastern Roman Empire with a seat in Odessus (present-day Varna, Bulgaria, Varna) established by Emperor Justinian I () on May 18, 536.
Territorially, the contained the Roman provinces o ...
''. 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
Samos (, also ; , ) is a Greek island in the eastern Aegean Sea, south of Chios, north of Patmos and the Dodecanese archipelago, and off the coast of western Turkey, from which it is separated by the Mycale Strait. It is also a separate reg ...
. It provided the bulk of the
Byzantine navy
The Byzantine navy was the Navy, naval force of the Byzantine Empire. Like the state it served, it was a direct continuation from its Roman navy, Roman predecessor, but played a far greater role in the defence and survival of the state than its ...
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
Thrace (, ; ; ; ) is a geographical and historical region in Southeast Europe roughly corresponding to the province of Thrace in the Roman Empire. Bounded by the Balkan Mountains to the north, the Aegean Sea to the south, and the Black Se ...
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
The Byzantine Empire was ruled by emperors of the dynasty of Heraclius between 610 and 711 AD. The Heraclians presided over a period of cataclysmic events that were a watershed in the history of the Empire and the world. Heraclius, the founder o ...
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
Sicily (Italian language, Italian and ), officially the Sicilian Region (), is an island in the central Mediterranean Sea, south of the Italian Peninsula in continental Europe and is one of the 20 regions of Italy, regions of Italy. With 4. ...
too was formed as a theme by the end of the 7th century, but the imperial possessions in mainland
Italy
Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...
remained under the exarch of Ravenna or the local ''doukes'', as did
Byzantine Africa until the fall of
Carthage
Carthage was an ancient city in Northern Africa, on the eastern side of the Lake of Tunis in what is now Tunisia. Carthage was one of the most important trading hubs of the Ancient Mediterranean and one of the most affluent cities of the classic ...
in 698. At the same time,
Crete
Crete ( ; , Modern Greek, Modern: , Ancient Greek, Ancient: ) is the largest and most populous of the Greek islands, the List of islands by area, 88th largest island in the world and the List of islands in the Mediterranean#By area, fifth la ...
and the imperial exclave of
Cherson in the
Crimea
Crimea ( ) is a peninsula in Eastern Europe, on the northern coast of the Black Sea, almost entirely surrounded by the Black Sea and the smaller Sea of Azov. The Isthmus of Perekop connects the peninsula to Kherson Oblast in mainland Ukrain ...
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
''Optimates'' (, ; Latin for "best ones"; ) and ''populares'' (; Latin for "supporters of the people"; ) are labels applied to politicians, political groups, traditions, strategies, or ideologies in the late Roman Republic. There is "heated ...
, 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
(; ) is a Greek-language work written by the 10th-century Byzantine Emperor Constantine VII. It is a domestic and foreign policy manual for the use of Constantine's son and successor, the Emperor Romanos II. It is a prominent example of Byz ...
''.
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
Basil II Porphyrogenitus (; 958 – 15 December 1025), nicknamed the Bulgar Slayer (, ), was the senior Byzantine emperor from 976 to 1025. He and his brother Constantine VIII were crowned before their father Romanos II died in 963, but t ...
(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
Armenians (, ) are an ethnic group indigenous to the Armenian highlands of West Asia.Robert Hewsen, Hewsen, Robert H. "The Geography of Armenia" in ''The Armenian People From Ancient to Modern Times Volume I: The Dynastic Periods: From Antiq ...
, 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
The ''katepánō'' (, ) was a senior Byzantine military rank and office. The word was Latinized as ''capetanus/catepan'', and its meaning seems to have merged with that of the Italian "capitaneus" (which derives from the Latin word "caput", mean ...
'', were set up. In the East, the three original such commands, set up by John Tzimiskes, were those of the ''doukes'' of
Antioch
Antioch on the Orontes (; , ) "Antioch on Daphne"; or "Antioch the Great"; ; ; ; ; ; ; . was a Hellenistic Greek city founded by Seleucus I Nicator in 300 BC. One of the most important Greek cities of the Hellenistic period, it served as ...
,
Chaldia and
Mesopotamia
Mesopotamia is a historical region of West Asia situated within the Tigris–Euphrates river system, in the northern part of the Fertile Crescent. Today, Mesopotamia is known as present-day Iraq and forms the eastern geographic boundary of ...
. As Byzantium expanded into
Greater Armenia in the early 11th century, these were complemented or replaced by the commands of
Iberia
The Iberian Peninsula ( ), also known as Iberia, is a peninsula in south-western Europe. Mostly separated from the rest of the European landmass by the Pyrenees, it includes the territories of peninsular Spain and Continental Portugal, compri ...
,
Vaspurakan,
Edessa
Edessa (; ) was an ancient city (''polis'') in Upper Mesopotamia, in what is now Urfa or Şanlıurfa, Turkey. It was founded during the Hellenistic period by Macedonian general and self proclaimed king Seleucus I Nicator (), founder of the Sel ...
and
Ani. In the same vein, the "Armenian" themes seem to have been placed under a single ''strategos'' in the mid-11th century.
The series of soldier-emperors culminating in Basil II led to a situation where by 1025 Byzantium was more powerful than any of its enemies. At the same time, the mobile, professional forces of the ''
tagmata'' gained in importance over the old thematic armies (and fleets) of the interior, which soon began to be neglected. Indeed, from the early 11th century military service was increasingly commuted to cash payments. While the frontier ducates were able to meet most local threats, the dissolution of the old theme-based defensive system deprived the Byzantine defensive system of any strategic depth. Coupled with increasing reliance on foreign mercenaries and the forces of allied and vassal states, as well as the revolts and civil wars resulting from the widening rift between the civilian bureaucracy in Constantinople and the land-holding military elites (the ''
dynatoi''), by the time of the
Battle of Manzikert
The Battle of Manzikert or Malazgirt was fought between the Byzantine Empire and the Seljuk Empire on 26 August 1071 near Manzikert, Iberia (theme), Iberia (modern Malazgirt in Muş Province, Turkey). The decisive defeat of the Byzantine army ...
in 1071, the Byzantine army was already undergoing a severe crisis and collapsed completely in the battle's aftermath.
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
The Byzantine army of the Komnenian era or Komnenian army was a force established by Byzantine emperor Alexios I Komnenos during the late 11th/early 12th century. It was further developed during the 12th century by his successors John II Komneno ...
' was established by
Alexios I Komnenos
Alexios I Komnenos (, – 15 August 1118), Latinization of names, Latinized as Alexius I Comnenus, was Byzantine Emperor, Byzantine emperor from 1081 to 1118. After usurper, usurping the throne, he was faced with a collapsing empire and ...
, 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
The Varangian Guard () was an elite unit of the Byzantine army from the tenth to the fourteenth century who served as personal bodyguards to the Byzantine emperors. The Varangian Guard was known for being primarily composed of recruits from Nort ...
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
The Komnenian restoration is the term used by historians to describe the military, financial, and territorial recovery of the Byzantine Empire under the Komnenian dynasty, from the accession of Alexios I Komnenos in 1081 to the death of Andron ...
required a new system to manage the severely weakened themes of
Anatolia
Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...
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
The ''pronoia'' (plural ''pronoiai''; Greek: πρόνοια, meaning "care", "forethought" or "providence," from πρό, "before," and νόος, "mind") was a system of granting dedicated streams of state income to individuals and institutions i ...
'' 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
Manuel I Komnenos (; 28 November 1118 – 24 September 1180), Latinized as Comnenus, also called Porphyrogenitus (; " born in the purple"), was a Byzantine emperor of the 12th century who reigned over a crucial turning point in the history o ...
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
The House of Palaiologos ( Palaiologoi; , ; female version Palaiologina; ), also found in English-language literature as Palaeologus or Palaeologue, was a Byzantine Greeks, Byzantine Greek Nobility, noble family that rose to power and produced th ...
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
The term ''thema'' was ambiguous, referring both to a form of military tenure and to an administrative division. A theme was an arrangement of plots of land given for farming to the soldiers "''stratiotai"'' coexisting with different villages and towns, "''Komai",'' "''Chora''" which were taxed for rapid and continuous revenue for the state with an easy and simple handling for a more direct control of the empire by the emperor alone or his
viceroys, which ultimately, was a simplified
Hellenistic
In classical antiquity, the Hellenistic period covers the time in Greek history after Classical Greece, between the death of Alexander the Great in 323 BC and the death of Cleopatra VII in 30 BC, which was followed by the ascendancy of the R ...
and fiscal administrative principle adapted for war times. The soldiers were still technically a military unit, under the command of a
strategos
''Strategos'' (), also known by its Linguistic Latinisation, Latinized form ''strategus'', is a Greek language, Greek term to mean 'military General officer, general'. In the Hellenistic world and in the Byzantine Empire, the term was also use ...
, they did not own the land they worked as it was still controlled by the state. Therefore, for its use the soldiers' pay was reduced. By accepting this proposition, the participants agreed that their descendants would also serve in the military and work in a theme, thus simultaneously reducing the need for unpopular
conscription
Conscription, also known as the draft in the United States and Israel, is the practice in which the compulsory enlistment in a national service, mainly a military service, is enforced by law. Conscription dates back to antiquity and it conti ...
as well as cheaply maintaining the military. It also allowed for the settling of conquered lands, as there was always a substantial addition made to public lands "''proasteion"'' during a conquest.
The commander of a theme, however, did not only command his soldiers. He united the civil and military jurisdictions in the territorial area in question. Thus the division set up by
Diocletian
Diocletian ( ; ; ; 242/245 – 311/312), nicknamed Jovius, was Roman emperor from 284 until his abdication in 305. He was born Diocles to a family of low status in the Roman province of Dalmatia (Roman province), Dalmatia. As with other Illyri ...
between civil governors (''praesides'' etc.) and military commanders (''duces'' etc.) was abolished, and the Empire returned to a system much more similar to that of the Republic or the Principate and directly linkeable to the system of
Eparchies
Eparchy ( ''eparchía'' "overlordship") is an ecclesiastical unit in Eastern Christianity that is equivalent to a diocese in Western Christianity. An eparchy is governed by an ''eparch'', who is a bishop. Depending on the administrative structure ...
and
Strategiai set up in the Hellenistic Seleucid and Mithridatric Kingdoms respectively, which were military in origin and organization as well, where provincial governors had also commanded the armies in their area.
The following table illustrates the thematic structure as found in the Thracesian Theme, c. 902-936:
List of the themes between c. 660 and 930
This list includes the large "traditional" themes established in the period from the inception of the theme system in c. 660 to the beginning of the great conquests in c. 930 and the creation of the new, smaller themes.
Notes:
† naval theme (in Greek , θέμα ναυτικόν)
§ Originally established as a ''kleisoura''
List of new themes, 930s–1060s
These were the new major or minor themes (provinces), established during the Byzantine conquests, in the East (the so-called "Armenian" themes or generalships, ), in Italy and in the Balkans.
Later themes, 12th–13th centuries
See also
*
*
Roman province
The Roman provinces (, pl. ) were the administrative regions of Ancient Rome outside Roman Italy that were controlled by the Romans under the Roman Republic and later the Roman Empire. Each province was ruled by a Roman appointed as Roman g ...
References
Sources
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{{Greek terms for country subdivisions
Types of administrative division
Military units and formations of the Byzantine Empire