* 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.

Schweitzer concludes that the 1st century theology, originating in the lifetimes of those who first followed Jesus, is both incompatible with, and far removed from, those beliefs later made official by the Roman Emperor Constantine in 325 CE.

By 325, the controversy had become significant enough that the Emperor Constantine called an assembly of bishops, the First Council of Nicaea, which condemned Arius ' doctrine and formulated the original Nicene Creed of 325.

Led by a pretender claiming to be Constantine Diogenes, a long-dead son of the Emperor Romanos IV, the Cumans crossed the mountains and raided into eastern Thrace until their leader was eliminated at Adrianople.

Soon afterwards he had the Empress Maria imprisoned and then killed ( forcing a signature from the child Emperor Alexius to put his mother to death ), by Pterygeonites and the hetaireiarches Constantine Tripsychos.

On the death of Emperor Constantine I, Athanasius was allowed to return to his See of Alexandria.

First exile: under Emperor Constantine, for 2. 5 years Jul 335 – 22 Nov 337 ; in Trier ( Germany ).

As a result of rises and falls in Arianism's influence after the First Council of Nicaea, Emperor Constantine I banished him from Alexandria to Trier in the Rhineland, but he was restored after the death of Constantine I by the emperor's son Constantine II.

The backstory of one of the surviving epistles, directed to Constantine I, recounts how the fame of Saint Anthony spread abroad and reached Emperor Constantine.

" Under the persistence of the brethren who told him, " Emperor Constantine loves the church ," he accepted to write him a letter blessing him, and praying for the peace and safety of the empire and the church.

The strategic significance of the strait was one of the factors in the decision of the Roman Emperor Constantine the Great to found there in AD 330 his new capital, Constantinople, which came to be known as the capital of the Eastern Roman Empire.

The location of Byzantium attracted Roman Emperor Constantine I who, in 330 AD, refounded it as an imperial residence inspired by Rome itself.

These mostly range in date from the beginning of the Greek Bronze Age ( about 3200 BC ) to the reign of the Roman Emperor Constantine I in the 4th century AD.

An Eastern Christianity | Eastern Christian Icon depicting Constantine I and Christianity | Emperor Constantine and the Fathers of the First Council of Nicaea ( 325 ) as holding the Niceno – Constantinopolitan Creed of 381.

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.

Constantinople was founded by the Roman Emperor Constantine I on the site of an already-existing city, Byzantium, settled in the early days of Greek colonial expansion, probably around 671 – 662 BC.

Emperor Constantine I presents a representation of the city of Constantinople as tribute to an enthroned Mary and Christ Child in this church mosaic.

* Constantine I, Roman Emperor from 306 to 337, commonly known as Constantine the Great

* Constantine II ( emperor ) ( 317 – 340 ), Roman Emperor 337 – 340

* Eskender ( 1471 – 1494 ), Emperor of Ethiopia sometimes known as Constantine II

Constantine Porphyrogenitus records in his work De Administrando Imperio that the Khazars asked the Emperor Teophilos to have the fortress of Sarkel built for them.

The first foreign writer to mention the city was the Emperor Constantine Porphyrogenitus.

Constantine VII Porphyrogennetos or Porphyrogenitus, " the Purple-born " (; September 2, 905 – November 9, 959 ) was the fourth Emperor of the Macedonian dynasty of the Byzantine Empire, reigning from 913 to 959.

Kotor ( then called " Cattaro ") has been fortified since the early Middle Ages, when Emperor Justinian built a fortress above Acruvium in 535, after expelling the Ostrogoths ; a second town probably grew up on the heights round it, for Constantine Porphyrogenitus, in the 10th century, alludes to Lower Kotor.

At the peaceful height of Middle Byzantium, court life " passed in a sort of ballet ", with precise ceremonies prescribed for every occasion, to show that " Imperial power could be exercised in harmony and order ", and " the Empire could thus reflect the motion of the Universe as it was made by the Creator ", according to the Emperor Constantine Porphyrogenitus, who wrote a Book of Ceremonies describing in enormous detail the annual round of the Court.

In the 10th century the Emperor Constantine Porphyrogenitus built another obelisk at the other end of the Hippodrome.

Porphyrogenitus wrote that Duklja had been made desolate by the Avars and " repopulated in the time of the Emperor Heraclius, just as were Croatia and Serbia " ( i. e. in the first half of the 7th century ).

During the reign of Emperor Constantine Porphyrogenitus ( 10th century ), Krk was known as Vekla, of which the Romanized variant, also used by the Venetians, was " Veglia ".

The History was used in the Excerpta de Legationibus of Emperor Constantine VII Porphyrogenitus ( r. 913 – 959 ), as well as by authors such as Evagrius Scholasticus, Cassiodorus, Jordanes, and the author of the Souda.

Constantine Porphyrogenitus records in his work “ On Administering the Empire ” that the Khagan and the Bek of the Khazars asked the Emperor Teophilos to have the fortress of Sarkel built for them.

Although, at least according to the testimony of the Byzantine Emperor Constantine Porphyrogenitus, Svatopluk had made a deathbed request to his sons that they remain united, after his death internal disagreements between his sons, Mojmír II and Svatopluk II were fostered by Arnulf.

Following the Hungarian conquest of the Carpathian Basin around 896, the title gyula can be found in the De administrando imperio (“ On the Governance of the Empire ”) written by the Byzantine Emperor Constantine Porphyrogenitus.

Mljet has been regarded as the " Melita " on which Saint Paul was shipwrecked ( Acts of the Apostles 27: 39-28: 11 ), this view being first expounded in the 10th century, by Eastern Roman Emperor Constantine Porphyrogenitus.

At its zenith under the Macedonian dynasty ( the 9th and 10th centuries ) the Byzantine world produced great heroes, but no great historians, excepting the solitary figure of the Emperor Constantine VII Porphyrogenitus.

These are the works under the name of the Emperor Constantine VII Porphyrogenitus ( 10th century ), dealing respectively with the administration of the empire, its political division, and the ceremonies of the Byzantine Court.

This encyclopedic activity was more assiduously pursued in the 10th century, particularly in the systematic collecting of materials associated with Emperor Constantine VII Porphyrogenitus.

Court life " passed in a sort of ballet ", with precise ceremonies prescribed for every occasion, to show that " Imperial power could be exercised in harmony and order ", and " the Empire could thus reflect the motion of the Universe as it was made by the Creator ", according to the Emperor Constantine Porphyrogenitus, who wrote a Book of Ceremonies describing in enormous detail the annual round of the Court.

Emperor Joseph I, acting on behalf of his younger brother King ’ Charles III ’, absent in Spain, claimed that reconquered Brabant and Flanders should be put under immediate possession of a governor named by himself.

After he became Emperor, Caligula claimed to have planned to kill Tiberius with a dagger in order to avenge his mother and brother: however, having brought the weapon into Tiberius's bedroom he did not kill the Emperor but instead threw the dagger down on the floor.

The Italian possession of maritime areas previously claimed by Abyssinia / Ethiopia was formalized in 1889 with the signing of the Treaty of Wuchale with Emperor Menelik II of Ethiopia ( r. 1889 – 1913 ) after the defeat of Italy by Ethiopia at the battle of Adua where Italy launched an effort to expand its possessions from Eritrea into the more fertile Abyssinian hinterland.

In 1936, the Italian king Victor Emmanuel III claimed the title of Emperor of Ethiopia after Ethiopia was occupied by Italy during the Second Italo-Abyssinian War.

Emperor Frederick II claimed the kingdom by marriage, but his presence sparked a civil war among the kingdom's nobility.

Some, including the Byzantine chronicler Theophanes, have claimed that Konon's family had been resettled in Thrace, where he entered the service of Emperor Justinian II, when the latter was advancing on Constantinople with an army of 15, 000 horsemen provided by Tervel of Bulgaria in 705.

` Abdu ' l-Bahá claimed that Mary travelled to Rome and spoke before the Emperor Tiberius, which is presumably why Pilate was later recalled to Rome for his cruel treatment of the Jews ( a tradition also attested to in the Eastern Orthodox Church ).

When Rudolph III, King of Burgundy died on 2 February 1032, Conrad II successfully claimed also this Kingship on the basis of an inheritance Emperor Henry II had extorted from the former in 1006, after having invaded Burgundy to enforce his claim after Rudolph attempted to renounce it in 1016.

In 800 Pope Leo III crowned the Frankish ruler Charlemagne as Roman Emperor, a major step toward establishing what later became known as the Holy Roman Empire ; from that date onward the popes claimed the prerogative to crown the Emperor, though the right fell into disuse after the coronation of Charles V in 1530.

The ravages of the Lombards rendered it very difficult to communicate with the Byzantine Emperor at Constantinople, who claimed the privilege of confirming the election of the popes.

As archbishop, he was appointed papal legate to France by Pope Paschal II during the time that Paschal was induced under pressure from Holy Roman Emperor Henry V to issue the Privilegium of 1111, by which he yielded much of the papal prerogatives that had been so forcefully claimed by Pope Gregory VII in the Gregorian Reforms.

Cyril Vladimirovich, Grand Duke of Russia, a descendant of Alexander II of Russia, claimed the title Emperor and Autocrat of all the Russias in 1924 and his descendant retains such claims.

After the death of Henry II ( 3 July 1024 ), Stephen broke with the German alliance, because the new Holy Roman Emperor, Conrad II claimed supremacy over the Kingdom of Hungary, while Stephen demanded the Duchy of Bavaria for his son Emeric who was the nearest relative of the deceased Emperor Henry II ( who himself had been the last male descendant of the old dukes of Bavaria ).

It appears the story was spread by Hubert Languet, who served as de Saxe under Emperor Charles V and then under the Prince of Orange, who claimed in 1565 that Vesalius was performing an autopsy on an aristocrat in Spain when it was found that the heart was still beating, leading to the Inquisition condemning him to death.

The chronicler also claimed that the duke secured the support of Emperor Henry IV and King Sweyn II of Denmark, but as Henry was still a minor and Sweyn was more likely to support Harold, who could then help Sweyn against the Norwegian king, these claims should be treated with caution.

* Commodus, Roman Emperor, claimed to be Hercules reincarnated

Powell further claimed that even if nuclear weapons had not existed, the Russians would still not have invaded Western Europe: " What has prevented that from happening was ... the fact that the Soviet Union knew ... that such an action on its part would have led to a third world war -— a long war, bitterly fought, a war which in the end the Soviet Union would have been likely to lose on the same basis and in the same way as the corresponding war was lost by Napoleon, by the Emperor Wilhelm and by Adolf Hitler.

Less experienced than Louis V, he was also challenged by the " False Waldemar ", an impostor who claimed Brandenburg and got support from several cities and Holy Roman Emperor Charles IV until the Wittelsbachs came to terms with Charles.

From 26 until 36 CE, Emperor Guangwu had to wage war against other regional warlords who claimed the title of emperor ; when these warlords were defeated, China reunified under the Han.

When Rudolph III, King of Burgundy died on 2 February 1032, Conrad claimed the Kingship on the basis of an inheritance Emperor Henry II extorted from the former in 1006, after having invaded Burgundy to enforce his claim after Rudolph attempted to renounce it in 1016.

# The Quadruple Alliance of April 1834 was formed by the United Kingdom, France, Spain, and Portugal to support queen Isabella II of Spain against her uncle Don Carlos, Count of Molina, who claimed the Spanish throne under the succession law of 1714-1830, and queen Maria II of Portugal ( represented by her father Pedro, 18th Duke of Braganza, former Emperor of Brazil and King of Portugal ) against her uncle Miguel of Portugal, who proclaimed himself absolute king before the Portuguese Liberal War.

The Emperor, who spent his entire reign securing the Pragmatic Sanction, left Austria in an impoverished state, bankrupted by the recent Turkish war and the War of the Polish Succession ; the treasury contained only 100, 000 florins, which were claimed by his widow.