Byzantine Greece The history of Byzantine Greece mainly coincides with the Eastern Roman or Byzantine Empire . Roman Greece . The Greek peninsula became a Roman protectorate in 146 BC , and the Aegean islands were added to this territory in 133 BC . Athens and other Greek cities revolted in 88 BC , and the peninsula was crushed by the Roman general Sulla . The Roman civil wars devastated the land even further , until Augustus organized the peninsula as the province of Achaea in 27 BC . Greece was a typical eastern province of the Roman Empire . The Romans sent colonists there and contributed new buildings to its cities , especially in the Agora of Athens , where the Agrippeia of Marcus Agrippa , the Library of Titus Flavius Pantaenus , and the Tower of the Winds , among others , were built . Romans tended to be philhellenic and Greeks were generally loyal to Rome . Life in Greece continued under the Roman Empire much the same as it had previously , and Greek continued to be the lingua franca in the Eastern and most important part of the Empire . Roman culture was heavily influenced by classical Greek culture ( see Greco - Roman ) as Horace said , " Graecia capta ferum victorem cepit " ( Translation : " " Captive Greece took captive her rude conqueror " " ) . The epics of Homer inspired the Aeneid of Virgil , and authors such as Seneca the younger wrote using Greek styles , while famous Romans such as Scipio Africanus , Julius Caesar and Marcus Aurelius compiled works in the Greek language . During that period , Greek intellectuals such as Galen or Apollodorus of Damascus were continuously being brought to Rome . Within the city of Rome , Greek was spoken by Roman elites , particularly philosophers , and by lower , working classes such as sailors and merchants . The emperor Nero visited Greece in 66 , and performed at the Olympic Games , despite the rules against non - Greek participation . He was , of course , honored with a victory in every contest , and in 67 he proclaimed the freedom of the Greeks at the Isthmian Games in Corinth , just as Flamininus had over 200 years previously . Hadrian was also particularly fond of the Greeks ; before he became emperor he served as eponymous archon of Athens . He also built his namesake arch there , and had a Greek lover , Antinous . At the same time Greece and much of the rest of the Roman east came under the influence of Christianity . The apostle Paul had preached in Corinth and Athens , and Greece soon became one of the most highly Christianized areas of the empire . Eastern Roman ( Byzantine ) Empire . During the second and third centuries , Greece was divided into provinces including Achaea , Macedonia , Epirus vetus and Thracia . During the reign of Diocletian in the late 3rd century , the western Balkans were organized as a Roman diocese , and was ruled by Galerius . Under Constantine I Greece was part of the dioceses of Macedonia and Thrace . The eastern and southern Aegean islands formed the province of Insulae in the Diocese of Asia . Greece faced invasions from the Heruli , Goths , and Vandals during the reign of Theodosius I . Stilicho , who acted as regent for Arcadius , evacuated Thessaly when the Visigoths invaded in the late 4th century . Arcadius ' Eutropius allowed Alaric to enter Greece , and he looted Corinth , and the Peloponnese . Stilicho eventually drove him out around 397 and Alaric was made " magister militum " in Illyricum . Eventually , Alaric and the Goths migrated to Italy , sacked Rome in 410 , and built the Visigothic Empire in Iberia and southern France , which lasted until 711 with the advent of the Arabs . Greece remained part of the relatively unified eastern half of the empire . Contrary to outdated visions of late antiquity , the Greek peninsula was most likely one of the most prosperous regions of the Roman and later the Eastern Roman / Byzantine Empire . Older scenarios of poverty , depopulation , barbarian destruction and civil decay have been revised in light of recent archaeological discoveries . In fact the " polis " , as an institution , appears to have remained prosperous until at least the sixth century . Contemporary texts such as Hierocles ' " Synecdemus " affirm that in late Antiquity , Greece was highly urbanised and contained approximately 80 cities . This view of extreme prosperity is widely accepted today , and it is assumed between the 4th and 7th centuries AD , Greece may have been one of the most economically active regions in the eastern Mediterranean . Following the loss of Alexandria and Antioch to the Arabs , Thessaloniki became the Byzantine Empire ' s second largest city , called the " co - regent " ( " symbasileuousa " ) , second only to Constantinople . The Greek peninsula remained one of the strongest centers of Christianity in the late Roman and early Byzantine periods . After the area ' s recovery from the Slavic invasions , its wealth was restored . Events such as the Seljuk invasion of Asia Minor and the Latin occupation of Constantinople gradually focused Byzantine imperial interest to the Greek peninsula during the late Byzantine period . The Peloponnese in particular continued to prosper economically and intellectually even during its Latin domination , the Byzantine recovery , and until its final fall to the Ottoman Empire . Further invasions and reorganization . Greece was raided in Macedonia in 479 and 482 by the Ostrogoths under their king , Theodoric the Great ( 493 - 526 ) . The Bulgars also raided Thrace and the rest of northern Greece in 540 and on repeated other occasions . These continuing Bulgar invasions required the Byzantine Empire to build a defensive wall , called the " Anastasian Wall , " that extended for some thirty ( 30 ) miles , or more , from the city of Selymbria ( now Silivri ) to the Black Sea . The Huns and Bulgars raided Greece in 559 until the Byzantine army returned from Italy , where Justinian I had been attempting to capture the heart of the Roman Empire . According to historical documents , the Slavs invaded and settled in parts of Greece beginning in 579 and Byzantium nearly lost control of the entire peninsula during the 580s . However , there is no archaeological evidence indicating Slavic penetration of imperial Byzantine territories before the end of the 6th century . Overall , traces of Slavic culture in Greece are very rare . The city of Thessaloniki remained unconquered even after being attacked by the Slavs around 615 . The Slavs were eventually defeated , gathered by the Byzantines and placed into segregated communities known as Sclaviniae . During the early 7th century , Constans II made the first mass - expulsions of Slavs from the Greek peninsula to the Balkans and central Asia Minor . Justinian II defeated and destroyed most of the Sclaviniae , and moved as many as 110 , 000 - 200 , 000 Slavs from the Greek peninsula to Bithynia , while he enlisted some 30 , 000 Slavs in his army . The Slavic populations that were placed in these segregated communities were used for military campaigns against the enemies of the Byzantines . In the Peloponnese , more Slavic invaders brought disorder to the western part of the peninsula , while the eastern part remained firmly under Byzantine domination . Empress Irene organised a military campaign which liberated those territories and restored Byzantine rule to the region , but it was not until emperor Nicephorus I ' s resettlement of some rural areas of Peloponnese with Greek - speakers from southern Italy , that the last trace of Slavic element was eliminated . In the mid - 7th century , the empire was reorganized into " themes " by the Emperor Constans II , including the Theme of Thrace , the naval " Karabisianoi " corps in southern Greece and the Aegean islands . The " Karabisanoi " were later divided by Justinian II into the Theme of Hellas ( centred on Corinth ) and the Cibyrrhaeotic Theme By this time , the Slavs were no longer a threat to the Byzantines since they had been either defeated numerous times or placed in the Sclaviniae . The Slavic communities in Bithynia were destroyed by the Byzantines after General Leontios lost to the Arabs in the Battle of Sebastopolis in 692 as a result of the Slavs having defected to the Arab side . These themes rebelled against the iconoclast emperor Leo III in 727 and attempted to set up their own emperor , although Leo defeated them . Leo then moved the headquarters of the " Karabisianoi " to Anatolia and created the Cibyrrhaeotic Theme of them . Up to this time Greece and the Aegean were still technically under the ecclesiastic authority of the Pope , but Leo also quarreled with the Papacy and gave these territories to the Patriarch of Constantinople . As emperor , Leo III , introduced more administrative and legal reforms than had been promulgated since the time of Justinian . Meanwhile the Arabs began their first serious raids in the Aegean . Bithynia was eventually re - populated by Greeks from mainland Greece and Cyprus . Bulgarian threat . Nicephorus I began to reconquer Slavic and Bulgar - held areas in the early 9th century . He resettled Greek - speaking families from Asia Minor to the Greek peninsula and the Balkans , and expanded the theme of Hellas to the north to include parts of Thessaly and Macedonia , and to the south to include the regained territory of the Peloponnese . Thessalonica , previously organized as an archon tate surrounded by the Slavs , became a theme of its own as well . These themes contributed another 10 , 000 men to the army , and allowed Nicephorus to convert most of the Slavs to Christianity . In the late 9th century Leo VI faced invasions from the Bulgarians under Simeon I , who pillaged Thrace in 896 , and again in 919 during Zoe ' s regency for Constantine VII . Simeon invaded northern Greece again in 922 and penetrated deep to the south seizing Thebes , just north of Athens . In the late 10th century the greatest threat to Greece was from Samuel , who constantly fought over the area with Basil II . In 985 Samuel captured Thessaly and the important city of Larissa , and in 989 he pillaged Thessalonica . Basil slowly began to recapture these areas in 991 , but Samuel captured the areas around Thessalonica and the Peloponnese again in 997 before being forced to withdraw to Bulgaria . In 999 Samuel captured Dyrrhachium and raided northern Greece once more . Basil recaptured these areas by 1002 and had fully subjugated the Bulgarians in the decade before his death . By Basil ’ s death in 1025 Greece was divided into " themes " including Crete , the Peloponnese , Hellas , Nicopolis , Larissa , Cephalonia , Thessalonica and Strymon , the Cyclades and the Aegean Sea . They were protected from raids and invasions by the new themes created out of Bulgar territory . Greece and Thrace became more prosperous in the 10th century and towns and cities began to grow again . Athens and Corinth probably grew to about 10 , 000 people , while Thessalonica may have had as many as 100 , 000 people . There was an important aristocratic class from these themes , especially the Macedonian emperors who ruled the empire from 867 to 1025 . Normans and Franks . Greece and the empire as a whole faced a new threat from the Normans of Sicily in the late 11th century . Robert Guiscard took Dyrrhachium and Corcyra in 1081 ( see Battle of Dyrrhachium ) , but Alexius I defeated him , and later his son Bohemund , by 1083 . The Pechenegs also raided Thrace during this period . In 1147 while the knights of the Second Crusade made their way through Byzantine territory , Roger II of Sicily captured Corcyra and pillaged Thebes and Corinth . In 1197 Henry VI of Germany continued his father Frederick Barbarossa ' s antagonism towards the empire by threatening to invade Greece to reclaim the territory the Normans had briefly held . Alexius III was forced to pay him off , although the taxes he imposed caused frequent revolts against him , including rebellions in Greece and the Peloponnese . Also during his reign , the Fourth Crusade attempted to place Alexius IV on the throne , until it eventually invaded and sacked the capital . Greece was relatively peaceful and prosperous in the 11th and 12th centuries , compared to Anatolia which was being overrun by the Seljuks . Thessalonica had probably grown to about 150 , 000 people , despite being looted by the Normans in 1185 . Thebes also became a major city with perhaps 30 , 000 people , and was the centre of a major silk industry . Athens and Corinth probably still had around 10 , 000 people . Mainland Greek cities continued to export grain to the capital in order to make up for the land lost to the Seljuks . However , after Constantinople was conquered during the Fourth Crusade in 1204 , Greece was divided among the Crusaders . The Latin Empire held Constantinople and Thrace , while Greece itself was divided into the Kingdom of Thessalonica , the Principality of Achaea , and the Duchy of Athens . The Venetians controlled the Duchy of the Archipelago in the Aegean , and the Despotate of Epirus was established as one of the three Byzantine Greek successor state s . Michael VIII restored the empire in 1261 , having also regained the Kingdom of Thessalonica . By his death in 1282 , Michael had taken back the Aegean islands , Thessaly , Epirus , and most of Achaea , including the Crusader fortress of Mystras , which became the seat of a Byzantine despotate . However , Athens and the northern Peloponnese remained in Crusader hands . Charles of Anjou and later his son claimed the throne of the defunct Latin Empire , and threatened Epirus and Greece , but were never able to make any progress there . Ottoman threat and conquest . Meanwhile the Ottoman Turks were threatening the empire and in 1303 the Catalan Grand Company under Roger de Flor offered to help defend against them . The Catalans and Byzantines never trusted each other , and the Catalans , and then also the Genoese , attacked the Byzantines throughout Greece and the Aegean . The Catalans also pillaged Thessaly in 1309 . By the reign of Andronicus III Palaeologus , beginning in 1328 , the empire controlled most of Greece , especially the metropolis of Thessalonica , but very little else . Epirus was nominally Byzantine but still occasionally rebelled , until it was fully recovered in 1339 . Greece was mostly used as a battleground during the civil war between John V Palaeologus and John VI Cantacuzenus in the 1340s , and at the same time the Serbs and Ottomans began attacking Greece as well . By 1356 another independent despotate was set up in Epirus and Thessaly . The Peloponnese , usually called Morea in this period , was now almost the centre of the empire , and was certainly the most fertile area . Mystras and Monemvasia were populous and prosperous , even after the Black Plague in the mid - 14th century . Mystras rivaled Constantinople in importance . It was a stronghold of Greek Orthodoxy and bitterly opposed attempts by the emperors to unite with the Roman Catholic Church , even though this would have allowed the empire to gain help from the west against the Ottomans . The Ottomans had begun their conquest of the Balkans and Greece in the late 14th century and early 15th century . In 1445 , Ottoman - occupied Thessaly was recaptured by future emperor Constantine XI , at the time despot of Mystras , but there was little he could do against most of the other Ottoman territories . Emperor Constantine was defeated and killed in 1453 when the Ottomans finally captured Constantinople . After the fall of Constantinople , the Ottomans also captured Athens and the Aegean islands by 1458 , but left a Byzantine despotate in the Peloponnese until 1460 . The Venetians still controlled Crete and some ports , but otherwise the Ottomans controlled many regions of Greece except the mountains and heavily forested areas .