Lack of stability was eminent in the southern Balkans as well : in 1341–1347 the Byzantine Empire was shaken Motion by a bloody civil war between John V Palaiologos and John VI Kantakouzenos .

In 1344 , Momchil , the independent Bulgarian ruler of the Rhodope and Aegean regions , whose army grew Expansion to 2,000 men , took Creating an important role in the Byzantine civil war .

During the Byzantine civil wars Ivan Alexander regained Recovering control Control over several towns in Thrace and the Rhodopes but his frequent interference in the internal affairs of Byzantium hampered Hindering any closer relations between the two counties despite the peace established Building in 1332 .

The Vandalic or Vandal War ( , `` Vandēlikòs Pólemos '' ) was a conflict fought Hostile_encounter in North Africa ( largely in modern Tunisia ) between the forces of the Eastern Roman or Byzantine Empire and the Vandalic Kingdom of Carthage , in 533–534 .

The Battle Hostile_encounter of Anzen or Dazimon was fought Hostile_encounter on 22 July 838 at Anzen or Dazimon ( now Dazmana ( Akçatarla ) , Turkey ) between the Byzantine Empire and the forces of the Abbasid Caliphate .

The Abbasids had launched Process_start a huge expedition Attack with two separate armies in retaliation for the Byzantine emperor Theophilos 's successes the previous year , and aimed Aiming to sack Destroying Amorion , one of Byzantium 's largest cities .

The numerically superior Byzantine army was initially successful , but when Theophilos resolved Resolve_problem to lead an attack Attack in person , his absence from his usual post caused Causation panic among the Byzantine troops , who feared that he had been killed Killing .

The numerically superior Byzantine army was initially successful , but when Theophilos resolved Resolve_problem to lead an attack Attack in person , his absence from his usual post caused Causation panic among the Byzantine troops , who feared that he had been killed Killing .

Coupled with a fierce counterattack Attack by Afshin 's Turkish horse-archers , the Byzantine army broke Destroying and fled Escaping .

The peasants ' leader Ivaylo , said Communication to had been a swineherd by the contemporary Byzantine chroniclers , proved Coming_to_believe to be a successful general and charismatic leader .

The Byzantine Emperor Michael VIII Palaiologos tried to exploit Control this situation to his favour and intervened Hindering in Bulgaria .

He sent Sending Ivan Asen III , son of the former Emperor Mitso Asen , to claim Statement the Bulgarian throne at the head of a large Byzantine army .

However , Ivaylo broke Destroying the siege Besieging and Ivan Asen III fled Escaping back to the Byzantine Empire .

Years after the demise Death of the peasant emperor , two `` Pseudo-Ivaylos '' appeared Presence in the Byzantine Empire and enjoyed Getting wide support Supporting by the populace .

The siege of Adrianople ( ) in 813 was a part of the wars of the Byzantine Empire with the Bulgarian khan Krum ( Byzantine-Bulgarian Wars ) .

It began Process_start soon after the Byzantine field army was defeated Earnings_and_losses in the battle of Versinikia on 22 June .

After an unsuccessful Byzantine attempt to murder Killing him ruined Destroying all prospects for negotiations with them , Krum ravaged Destroying much of Eastern Thrace and then turned Change against Adrianople which was still under siege Besieging .

The city—one of the most important Byzantine fortresses in Thrace—held out for a while despite being attacked Attack with siege engines .

Under the peace treaty , concluded Process_end in 815 , Adrianople remained in the Byzantine empire .

The Fall Conquering of Constantinople ( ; ) was the capture Conquering of the capital city of the Byzantine Empire by an invading Attack Ottoman army on the Sunday of Pentecost , 29 May 1453 .

The capture Conquering of the city ( and two other Byzantine splinter territories soon thereafter ) marked Recording the end Process_end of the Roman Empire , a state which dated to 27 BC , which had lasted for nearly 1,500 years .

The conquest Conquering of the city of Constantinople and the end Process_end of the Byzantine Empire was a key event in the Late Middle Ages which also marks , for some historians , the end Process_end of the Medieval period .

970 until 1018 , a series of conflicts Hostile_encounter between the Bulgarian Empire and the Byzantine Empire led to Causation the gradual conquest Conquering of Bulgaria by the Byzantines , who thus re-established Recovering their control Control over the entire Balkan peninsula for the first time since the 7th-century Slavic invasions Attack .

Bulgarian resistance Defending was led by the Cometopuli brothers , who based Causation in the unconquered western regions of the Bulgarian Empire led it until its fall under Byzantine rule Control in 1018 .

Emperor Boris II was captured Conquering and taken Bringing to Constantinople where he abdicated Change_of_leadership and the Byzantine Emperor John I Tzimiskes announced Expressing_publicly the annexation Change_of_leadership of Bulgaria , even though the Eastern Roman Empire only controlled Control Eastern Bulgaria at the time , but the lands to the west remained under Bulgarian control Control .

Samuel proved Causation to be a successful general inflicting Causation a major defeat on the Byzantine army commanded by Basil II at the Gates of Trajan and retaking north-eastern Bulgaria .

By the end of the millennium the fortunes of war Military_operation turned Becoming into Byzantine favour .

The Bulgarians were unable to stop Preventing_or_letting the annual Byzantine campaigns Military_operation which devastated Destroying the country .

In 1018 , Ivan Vladislav 's widow , Maria , negotiated Communication very favorable terms of surrender Surrendering to the Byzantine emperor .

All local lords who surrendered Surrendering were transferred Sending either to Constantinople or to Anatolia and most of them were later assimilated Cause_to_amalgamate into the Byzantine society .

Its western part was transformed Change into one of the many Byzantine 's provinces , which was ruled Control by a governor appointed by the Emperor .

The Abbasid campaign was led Causation personally by the Caliph al-Mu'tasim ( reigned 833–842 ) , in retaliation Revenge to a virtually unopposed expedition launched Motion by the Byzantine emperor Theophilos ( r. 829–842 ) into the Caliphate 's borderlands the previous year .

Mu'tasim targeted Aiming Amorium , a Byzantine city in western Asia Minor ( modern Anatolia ) , because it was the birthplace of the ruling Byzantine dynasty and , at the time , one of Byzantium 's largest and most important cities .

Mu'tasim targeted Aiming Amorium , a Byzantine city in western Asia Minor ( modern Anatolia ) , because it was the birthplace of the ruling Byzantine dynasty and , at the time , one of Byzantium 's largest and most important cities .

The northeastern army defeated Conquering the Byzantine forces under Theophilos at Anzen , allowing Preventing_or_letting the Abbasids to penetrate deep into Byzantine-held Asia Minor and converge upon Ancyra , which they found Know abandoned GiveUp .

The Seljuq campaigns Military_operation in the Aegean refer Name_conferral to the ground and naval actions conducted Action by the Seljuk Turks , chiefly under the leadership of Tzachas of Smyrna against the Byzantine Empire .

The Sasanian Empire conquered Conquering Jerusalem after a brief siege in 614 , during the Byzantine–Sasanian War of 602–628 , after the Persian Shah Khosrau II appointed Change_of_leadership his general Shahrbaraz to conquer Conquering the Byzantine controlled areas of the Near East .

Some 20,000 Jewish rebels joined Becoming_a_member the war against the Byzantine Christians .

In a series of three stages , the conquest Conquering of the Maghreb commenced Process_start in 647 and concluded Process_end in 709 with the `` Byzantine '' Roman Empire losing Earnings_and_losses its last remaining Presence strongholds to the then-Umayyad Caliphate .

By 642 AD , under Caliph Umar , Arab Muslim forces had laid Placing control Control of Mesopotamia ( 638 ) , Syria ( 641 ) , Egypt ( 642 ) , and had invaded Attack Armenia , all previously territories split Motion between the warring Hostile_encounter Byzantine and Persian Empires , and were concluding Process_end their conquest Conquering of the Persian Empire with their defeat Conquering of the Persian army at the Battle Hostile_encounter of Nahāvand .

The Byzantine navy would be defeated Conquering in the eastern Mediterranean .

The Uprising of Asen and Peter ( ) was a revolt of Bulgarians and Vlachs living in Moesia and the Balkan Mountains , then the theme of Paristrion of the Byzantine Empire , caused Causation by a tax increase .

They asked Request to be added Cause_to_be_included to the roll of the Byzantine army and to be granted Giving land near Haemus to provide Supply the monetary income needed to pay Cost the tax .

The brothers Peter and Asen built Building the Church of St Demetrius of Thessaloniki in Tarnovo , dedicated Giving to Saint Demetrius , who was traditionally considered a patron of the Byzantine city of Thessaloniki , and claimed Statement that the Saint had ceased Process_end to favour the Byzantines : `` God had decided Deciding to free Releasing the Bulgarians and the Vlach people and to lift Process_end the yoke that they had borne Bringing for so long '' .

This persuaded Convincing their followers to attack Attack Byzantine cities , seizing Hold prisoners and cattle .

The lands between the Haemus and the Danube were now lost Earnings_and_losses for the Byzantine Empire , leading to Causation the signing of a truce , thus de facto recognising Know the rule of the Asen and Peter over the territory , leading to Causation the creation of the Second Bulgarian Empire .

Urban called Request for a military expedition Conquering to aid Assistance the Byzantine Empire , which had recently lost Earnings_and_losses most of Anatolia to the Seljuq Turks .

The expedition Conquering was a reaction Response to the appeal Statement for military aid by Byzantine Emperor Alexios I Komnenos .

The Arab–Byzantine wars Hostile_encounter were a series of wars Hostile_encounter between the mostly Arab Muslims and the Byzantine Empire between the 7th and 11th centuries AD , started Process_start during the initial Muslim conquests under the expansionist Rashidun and Umayyad caliphs in the 7th century and continued by their successors until the mid-11th century .

With the decline Cause_change_of_position_on_a_scale and fragmentation of the Abbasid state after 861 and the concurrent strengthening Cause_change_of_strength of the Byzantine Empire under the Macedonian dynasty , the tide gradually turned Becoming .