* 681 – Bulgaria is founded as a Khanate on the south bank of the Danube after defeating the Byzantine armies of Emperor Constantine IV south of the Danube delta.

* 527 – Byzantine Emperor Justin I names his nephew Justinian I as co-ruler and successor to the throne.

* 1091 – Battle of Levounion: The Pechenegs are defeated by Byzantine Emperor Alexius I.

* 1018 – Byzantine general Eustathios Daphnomeles blinds and captures Ibatzes of Bulgaria by a ruse, thereby ending Bulgarian resistance against Emperor Basil II's conquest of Bulgaria.

* Alexander, Byzantine Emperor ( 912 – 913 )

* Alexander ( emperor ), Byzantine Emperor ( 912 – 913 )

Alexios II Komnenos or Alexius II Comnenus () ( 10 September 1169 – 24 September 1183, Constantinople ), Byzantine emperor ( 1180 – 1183 ), was the son of Emperor Manuel I Komnenos and Maria, daughter of Raymond, prince of Antioch.

Alexios III Angelos () ( c. 1153 – 1211 ) was Byzantine Emperor from 1195 to 1203.

Alexios V Doukas, surnamed Mourtzouphlos (, d. December 1205, Constantinople ) was Byzantine Emperor ( 5 February – 12 April 1204 ) during the second and final siege of Constantinople by the participants of the Fourth Crusade.

He was the last Byzantine Emperor to reign in Constantinople before the establishment of the Latin Empire, which controlled the city for the next 57 years, until it was recovered by the Nicaean Emperor Michael VIII Palaiologos.

* Anastasius I ( emperor ) ( 430 – 518 ), Roman ( Byzantine ) Emperor from 491 to 518

In spite of several not insignificant reverses at the hands of Bulgarians, Serbians, and Ottomans, the Emperor had provided the Empire with active leadership, had cooperated with able administrators, and had come closer than any of his predecessors in re-establishing Byzantine control over the Greek peninsula.

Andronikos I Komnenos ( or Andronicus I Comnenus, ; c. 1118 – September 12, 1185 ) was Byzantine Emperor from 1183 to 1185 ).

However, as Andronikos ' rule went on, the Emperor became increasingly paranoid and violent – in September 1185, Andronikos ordered the execution of all prisoners, exiles and their families for collusion with the invaders – and the Byzantine Empire descended into a terror state.

* 475 – Byzantine Emperor Basiliscus issues a circular letter ( Enkyklikon ) to the bishops of his empire, supporting the Monophysite christological position.

Arcadius (; ; 377 / 378 – 1 May 408 ) was the Byzantine Emperor from 395 until his death in 408.

This could be either the normal military dress, with a tunic to about the knees, armour breastplate and pteruges, but also often the specific dress of the bodyguard of the Byzantine Emperor, with a long tunic and the loros, a long gold and jewelled pallium restricted to the Imperial family and their closest guards.

* 491 – Flavius Anastasius becomes Byzantine Emperor, with the name of Anastasius I.

According to the work De Administrando Imperio written by the 10th-century Byzantine Emperor Constantine VII, the Croats had arrived in what is today Croatia in the early 7th century, however that claim is disputed and competing hypotheses date the event between the 6th and the 9th centuries.

In the sixth century, the Byzantine Emperor Justinian oversaw the consolidation of Roman civil law.

At the Istanbul Archaeological Museum a marble plate contains a law by the Byzantine Emperor Anastasius I ( 491-518 AD ), that regulated fees for passage through the customs office of the Dardanelles ( see image to the right ).

* 1025 – Basil II, Byzantine Emperor ( b. 958 )

* 627 – Battle of Nineveh: A Byzantine army under Emperor Heraclius defeats Emperor Khosrau II's Persian forces, commanded by General Rhahzadh.

Heraclius (,, c. 575 – February 11, 641 ) was Byzantine Emperor from 610 to 641.

Serving their partner in wars against the Abbasid Caliphate, Khazars aided the Byzantine emperor Heraclius ( reigned 610 – 641 ) by sending an army of 40, 000 soldiers in their campaign against the Persians in the Byzantine – Sassanid War of 602 – 628.

When the Byzantine or Eastern Roman emperor Heraclius ejected the Persians in 630 AD, he expelled the city's Jews.

* 610 – Heraclius arrives by ship from Africa at Constantinople, overthrows Byzantine Emperor Phocas and becomes Emperor.

* 610 – Coronation of Byzantine Emperor Heraclius.

He supported a formula proposed by the Byzantine Emperor Heraclius with the design of bringing about a reconciliation between Monothelites and the rest of the Catholic Church.

* Τhe Byzantine Emperor Heraclius campaigns to Cappadocia and defeats the Sassanid army.

* Croats and Serbs settle in the Balkans, having been invited by the Byzantine emperor Heraclius.

* Byzantine Empire: August – Justinian II and his ally, the Bulgar khan Tervel, by-pass the Byzantine forces under Heraclius awaiting them and reach Constantinople.

* Byzantine Empire: The Byzantine general Heraclius defeats and destroys an Umayyad army at Sisium.

* February 11 – Byzantine Emperor Heraclius dies.

* February 11 – Heraclius, Byzantine emperor

* Eudoxia Epiphania, the only daughter of the Byzantine Emperor Heraclius and his first wife Eudokia.

* May 3 – Heraclius Constantine, first son of Byzantine Emperor Heraclius, and himself a future Emperor

* The Byzantine emperor Heraclius marries his niece Martina.

* Autumn – winter – The Byzantine general Heraclius, brother of Tiberius III, launches a campaign into Syria, defeats an army from Antioch and raids as far as Samosata.

In 635, Kubrat signed a peace treaty with emperor Heraclius of the Byzantine Empire, expanding the Bulgar kingdom further into the Balkans.

Some prominent Byzantine aristocrats came to meet Heraclius, and he arranged to be crowned and acclaimed as Emperor.