Justinian campaigns (533–555): The Eastern Roman emperor Justinian launched an ambitious reconquest of Italy, North Africa and parts of Spain. However, new invaders like the Avars, Lombards and Slavs, alongside a pandemic known as the Plague of Justinian and various volcanicwinters ended his ambition of recuperate the West and consolidate the reconquest.
By 650 (pictured) the Eastern Roman (Byzantine) empire had lost all its southern provinces, except the Exarchate of Africa, to the Rashidun Caliphate. At the same time the Slavs invaded and settled in the Balkans. The losses continued in the next century
The Eastern Roman emperor Heraclius adopted the Greek language as official language in 610. Constantinople's territorial control shrunk to Greece and Anatolia, because of Persian, Avar and finally Arab invasions. Due to these changing circumstances, the reign of Heraclius is often regarded as the turning point from which historiography stops calling it the "Eastern Roman Empire", and starts speaking of the "Byzantine Empire".[1]
645–656: Renewed war with the Caliphate, loss of Cyprus and most of Armenia. The Rashidun advance towards Constantinople halted following the outbreak of the First Fitna.
668–678: Renewed attacks on the Byzantine Empire by Muawiyah II, leading to the First Arab Siege of Constantinople. Following its failure, a truce was agreed, providing for payment of tribute, men and horses to the Empire.
686–688: Successful Byzantine offensive established Byzantine control over Armenia and Caucasian Iberia, followed by favourable peace agreement with the Umayyad Caliphate, in return for the withdrawal of the Mardaites into the Empire.
688–689: Balkan campaign of Justinian II secured the coast between Thrace and Macedonia. Many Slavs were captured and resettled in imperial territory. Over 30,000 were incorporated into the Byzantine army.
689: Justinian II leads his army into Syria when Abd al-Malik ibn Marwan stops the payment of tributes due to Mardaites raids. Approximately 12,000 Mardaites are deported to the Empire. Peace is re-established and tributes resumed.
692–718: Almost constant war with the Arabs in various fronts. The defeat at the Battle of Sebastopolis and internal instability led to the gradual loss of Armenia and Cilicia, and despite some successes by Emperor Heraclius, the Byzantines generally maintained a defensive stance against the annual Arab raids into Anatolia. Carthage fell in 697. Recovered soon after, it was again lost in 698, marking the end of Byzantine North Africa. From 712 on, the Arab raids penetrated ever deeper into Anatolia, with the final objective of mounting an assault on Constantinople itself. The repulsion of the Second Arab Siege of Constantinople (717–718) was a major Byzantine success. Consider to be one of history's most important battles, the victory halted Muslim advance into Southeastern Europe for centuries.
8th century
708: War with Bulgaria ends in defeat at Anchialus.
720–740 : Annual Arab raiding expeditions (ṣawā'if) against Byzantine Anatolia resume. Stiffening Byzantine resistance leads to the victory at Akroinon at 740.
741–752: Campaigns of Constantine V against the Arabs, who were embroiled in civil war, leading to the recovery of all of Armenia and Cyprus.
755–767: War with the Bulgars. Constantine V defeats the Bulgar khan Telets, leading to the conclusion of a favourable peace treaty in 767.
772–775: War with the Bulgars under Telerig, launched as a pre-emptive strike by Constantine V.
775–783: War with the Abbasids. After the death of Constantine V in 775, Arab raids resumed. After a heavy defeat at Germanicopolis in 779/780, the Abbasids launched a series of major invasions under Harun al-Rashid, which led to the conclusion of a truce in 783.
780–783: Raids by the Bulgars under Kardam, leading to an agreement of non-aggression in exchange for annual payments.
797–798: Large-scale invasion by Harun al-Rashid leads to the resumption of annual payments to the Caliphate in return for peace.
9th century
803–809: War with the Abbasids, resulting from Nikephoros I's cessation of annual tribute payments. The Arabs under Harun al-Rashid achieved significant early successes, but the outbreak of a revolt in Khorasan facilitated a Byzantine counter-offensive in 807–809. A truce in 809 restored the territorial status quo.
808–816: Wars with the Bulgars, beginning with the Bulgarian capture of Sofia. A large-scale retaliatory campaign ended in the disastrous battle of Pliska (811), following which Krum of Bulgaria raided Eastern Thrace and secured a major victory at Versinikia. Following his death in 814, Leo V the Armenian defeated the Bulgars at Mesembria and secured a 30-year peace.
830–841: War with the Abbasids, with large-scale invasions launched by caliphs al-Ma'mun and al-Mu'tasim. Despite a crushing defeat at the Battle of Dazimon and the sack of Amorium in 838, Emperor Theophilos was able to conclude a truce in 841 without territorial losses, although raids by the Muslim border emirates continued.
ca. 844–878: Wars with the Paulicians of Tephrike end with the destruction of the Paulician state and its incorporation into the Empire.
851–863: War with the Abbasids and their clients. Successful Byzantine raids in Syria, Mesopotamia and Egypt are checked by a series of Muslim invasions of Anatolia in 860. Another invasion in 863 sees the complete annihilation of the Muslim army at the Battle of Lalakaon.
852, 855–856: Short wars with Bulgaria, ending in the recovery of several cities in northern Thrace.
871–885: Campaigns led by Basil I in person against northern Mesopotamia (871–873) are followed by a series of expeditions against the Muslims in Sicily and Southern Italy. The final loss of Sicily could not be averted, but the Arabs are driven from Southern Italy and Dalmatia, laying the foundations of the Catepanate of Italy.
894–896/897: War with Bulgaria under Tsar Simeon erupts over trade rights. It ends with a Bulgarian victory after the Battle of Bulgarophygon. The Byzantines agree to pay tribute and restore the market for Bulgarian goods to Constantinople.
964–975: Sustained Byzantine offensive in the East, under Nikephoros II Phokas and John I Tzimiskes, leads to the conquest of Cilicia, Cyprus, much of western Armenia and northern Syria. Aleppo becomes an imperial vassal.
992–999: War with the Fatimids over Aleppo. Initial Fatimid victories over Michael Bourtzes lead to the direct intervention of Basil II, who clears northern Syria of the Fatimids and secures a ten-year truce
11th century
1014: Battle of Kleidion decisive victory over the Bulgarians under Samuel.
1068-1071: Siege of Bari The Normans conquered Bari and put an end to the Catepanate of Italy.
1071: Battle of Mantzikert The Seljuk Turks defeated the Byzantines and began the invasion of Anatolia.
1078: Suleyman creates the Sultanate of Rum after conquering Nicaea.
1081–1085: War against the first Norman invasion of the Balkans. Early Byzantine defeat at Dyrrhachium (1081), but the successful defence of Thessaly and naval victories with Venetian aid led to the eventual abandonment of the invasion after the death of Robert Guiscard.
1086–1091: Uprising of the Bogomils in the Balkans, aided by the Cumans and Pechenegs. Early Byzantine defeat at Dristra (1086), but the Pechenegs were decisively defeated at the Battle of Levounion in 1091.
1096–1097: The First Crusade passed through Byzantium on its way to the Holy Land. Recovery of Nicaea with the Crusaders' aid, and subsequent reconquest of much of western Asia Minor by John Doukas.
1110–1117: Renewed war with the Seljuk Turks. Initial Turkish advances are reversed in a treaty concluded after the Byzantine victory at the Battle of Philomelion.
1124–1126: War with Venice over the non-renewal of trading privileges by John II Komnenos. The Venetian fleet ravaged the coasts of Greece, forcing the emperor to back down.
1171–1177: War with Venice. Initial Venetian moves in the Aegean checked by the Byzantine fleet. Truce concluded in 1177, peace treaty in 1183.
1176–1180: War with the Seljuks. Initial campaign against ends in the defeat at the Battle of Myriokephalon, resulting in the gradual loss of territory in Anatolia.
1235: Joint Nicaean-Bulgarian siege of Constantinople fails
1254–1256: Bulgaria attacks Nicaea after the death of John III Vatatzes, in an attempt to recover lost territory. Emperor Theodore II Laskaris campaigns against the Bulgarians and drives them back.
ca. 1272–1280: Campaigns of Licario recover Euboea and many Aegean islands for the Empire.
sometime in 1273–1275: Large-scale campaign against John I Doukas of Thessaly. The Byzantine army is defeated at Neopatras, but the navy scores a major victory at Demetrias.
1274–1275: Byzantine offensive against Angevin holdings in Albania drive the Angevin forces out of most of the country, although repeated assaults on their last two strongholds of Dyrrhachium and Valona fail.
1279: Unsuccessful campaigns against Bulgaria, defeat at Devina.
1280–1281: Angevin offensive in Albania is repulsed at Berat, and most of Albania is retaken.
1302–1305: War with the Ottoman Turks. After a defeat in the Battle of Bapheus, the Byzantines hire the Catalan Company. After a series of victories against the Turks, the Catalans turn against Byzantium following the murder of their leader.
1304–1305: The Bulgarians attack Byzantium, and manage to recover the port cities on the Black Sea coast.
1326–1338: Gradual capture of the remaining Byzantine cities in northwestern Anatolia by the Ottomans, Bursa in 1326, Nicaea in 1331 and Nicomedia in 1337. Defeats of the Byzantines in battles at Pelekanon and Philokrene.
