Eastern Roman emperor in the context of "Basiliscus"

Zeno (/ˈziːnoʊ/; Ancient Greek: Ζήνων, romanized: Zénōn; c. 425 – 9 April 491) was Eastern Roman emperor from 474 to 475 and again from 476 to 491. His reign was plagued by domestic revolts and religious dissension, but was more successful on the foreign front. He is credited with further stabilizing the Eastern empire, while the Western Roman Empire fell following the deposition of Romulus Augustulus.

Born in Isauria, Zeno was known as Tarasis before adopting his Greek name and becoming an ally of Emperor Leo I, who saw the Isaurian general as an important counterweight against the Germanic leader Aspar. In 466, he married Leo I's daughter, Ariadne, with whom he had a son, Leo. On the death of Leo I in 474, Zeno's seven-year-old son took the throne as Leo II, with Zeno made co-emperor shortly after. Leo II died of an illness later that year, leaving Zeno as the sole emperor.

The Typos of Constans (also called Type of Constans) was an edict issued by Eastern Roman emperor Constans II in 648 in an attempt to defuse the confusion and arguments over the Christological doctrine of Monotheletism. For over two centuries, there had been a bitter debate regarding the nature of Christ: the orthodox Chalcedonian position defined Christ as having two natures in one person, whereas Miaphysite opponents contended that Jesus Christ possessed but a single nature. At the time, the Byzantine Empire had been at near constant war for fifty years and had lost large territories. It was under great pressure to establish domestic unity. This was hampered by the large number of Byzantines who rejected the Council of Chalcedon in favour of Monophysitism.

The Typos attempted to dismiss the entire controversy, on pain of dire punishment. This extended to kidnapping the Pope from Rome to try him for high treason and mutilating one of the Typos's main opponents. Constans died in 668. Ten years later his son, Constantine IV, fresh from a triumph over his Arab enemies and with the predominantly Monophysitic provinces irredeemably lost, called the Third Council of Constantinople. It decided with an overwhelming majority to condemn Monophysitism, Monotheletism, the Typos of Constans and its major supporters. Constantine put his seal to the Council's decisions, and reunited such of Christendom as was not under Arab suzerainty.

Totila, original name Baduila (died 1 July 552), was the penultimate King of the Ostrogoths, reigning from 541 to 552. A skilled military and political leader, Totila reversed the tide of the Gothic War, recovering by 543 almost all the territories in Italy that the Eastern Roman Empire had captured from his Kingdom in 540.

A grandnephew of Theudis, sword-bearer of Theodoric the Great and king of the Visigoths, Totila was elected king by Ostrogothic nobles in the autumn of 541 after the deaths of Kings’ Ildibad & Eraric. Both had been killed by the Gothic nobility for attempting to surrender to the Romans. Totila proved himself both as a military and political leader, winning the support of the lower classes by liberating slaves and distributing land to the peasants. After a successful defence at Verona, Totila pursued and defeated a numerically superior army at the Battle of Faventia in 542. Totila followed these victories by defeating the Romans outside Florence and capturing Naples. By 543, fighting on land and sea, he had reconquered the bulk of the lost territory. Rome held out, and Totila appealed unsuccessfully to the Senate in a letter reminding them of the loyalty of the Romans to his predecessor Theodoric the Great. In the spring of 544, the Eastern Roman emperor Justinian I sent his general Belisarius to Italy to counterattack, but Totila captured Rome in 546 from Belisarius and depopulated the city after a yearlong siege. When Totila left to fight the Byzantines in Lucania, south of Naples, Belisarius retook Rome and rebuilt its fortifications.

Maurice (Latin: Mauricius; Ancient Greek: Μαυρίκιος, romanized: Maurikios; 539 – 27 November 602) was Eastern Roman emperor from 582 to 602 and the last member of the Justinian dynasty. A successful general, Maurice was chosen as heir and son-in-law by his predecessor Tiberius II.

Maurice's reign was troubled by almost constant warfare. After he became emperor, he brought the war with Sasanian Persia to a victorious conclusion. The empire's eastern border in the South Caucasus was vastly expanded and, for the first time in nearly two centuries, the Romans were no longer obliged to pay the Persians thousands of pounds of gold annually for peace.

Phocas (Latin: Focas; Ancient Greek: Φωκάς, romanized: Phōkás; 547 – 5 October 610) was Eastern Roman emperor from 602 to 610. Initially a middle-ranking officer in the Roman army, Phocas rose to prominence as a spokesman for dissatisfied soldiers in their disputes with the court of the Emperor Maurice. When the army rebelled in 602, Phocas emerged as the leader of the mutiny. The revolt led to the overthrow and execution of Maurice in November 602.

Phocas deeply mistrusted the uncooperative elite of Constantinople, to whom he was a usurper and a provincial boor. He therefore attempted to base his regime on relatives installed in high military and administrative positions. He immediately faced challenges in domestic and foreign affairs, and responded with little success. He dealt with domestic opposition with increasing ruthlessness that alienated ever wider circles, including some of his own household. The Sasanian Empire launched a massive invasion of the eastern provinces. Finally, the exarch of Africa, Heraclius the Elder, rebelled against Phocas and gained wide support throughout the empire. Phocas attempted to use border troops to crush the rebellion, but this only resulted in allowing invaders to break into the heartlands of the Empire. Heraclius the Elder's son, Heraclius, took Constantinople on 5 October 610, executed Phocas the same day, and declared himself emperor.