* 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.

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.

* Constantine IV

* Constantine II, King of Armenia, also called Constantine IV

* Constantine IV, King of Armenia, also called Constantine VI

* Patriarch Constantine IV of Constantinople

The council began when Emperor Constantine IV, wanting to heal the schism that separated the two sides, wrote to Pope Donus suggesting a conference on the matter, but Donus was dead by the time the letter arrived.

Agatho also undertook negotiations between the Holy See and Constantine IV concerning the relations of the Byzantine Court to papal elections.

Although chosen in 683, he was not ordained until 684 because the permission of Emperor Constantine IV was not obtained until some months after the election.

* Leo IV succeeds Constantine V as Byzantine Emperor.

* Constantine IV, Byzantine emperor

* September – Justinian II succeeds Constantine IV as emperor of the Byzantine Empire.

* September – Constantine IV, Byzantine emperor ( b. 652 )

* Constantine IV, son of Constans II, becomes Byzantine Emperor, succeeding Constans II.

These negotiations were undertaken by Leo's predecessor Agatho between the Holy See and Emperor Constantine IV.

After Constans ' son and successor, Constantine IV had overcome the Muslim siege of Constantinople in 678, he immediately set his sights on restoring communion with Rome: he wrote to Pope Donus suggesting a conference on the matter.

Emperor Constantine IV.

With Constans ' death in 668, the throne passed to his son Constantine IV.

Justinian II was an ambitious and passionate ruler who was keen to restore the Empire to its former glories, but he responded poorly to any opposition to his will and lacked the finesse of his father, Constantine IV.

Justinian II was the eldest son of Emperor Constantine IV and Anastasia.

Constantine VI was the only son of Leo IV and succeeded him as emperor, ruling jointly with his mother, Irene.

In 1067, he had been considered as a possible husband for the empress Eudokia Makrembolitissa, widowed wife of Constantine X, but she eventually set her heart on Romanos IV Diogenes.

To solidify his position, on the death of his second wife Nikephoros III sought to marry Eudokia Makrembolitissa, the mother of Michael VII and the widow of Constantine X and Romanos IV.

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.

Although he was committed to maintaining what the church had defined at Nicaea, Constantine was also bent on pacifying the situation and eventually became more lenient toward those condemned and exiled at the council.

At the First Synod of Tyre in AD 335, they brought accusations against Athanasius, bishop of Alexandria, the primary opponent of Arius ; after this, Constantine had Athanasius banished, since he considered him an impediment to reconciliation.

Eusebius and Theognis remained in the Emperor's favour, and when Constantine, who had been a catechumen much of his adult life, accepted baptism on his deathbed, it was from Eusebius of Nicomedia.

* Constantine Humbertopoulos, who had assisted Alexios in gaining the throne in 1081 conspired against him in 1091 with an Armenian called Ariebes.

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.

The antipope Felix died, as stated above, on a 22 November, and his death was not a martyr's, occurring when the Peace of Constantine had been in force for half a century.

Arnulf then proceeded to exile to Bavaria two leading senators, Constantine and Stephen, who had helped Ageltrude seize the city.

Facing the danger of encirclement, Constantine realized that his army could no longer continue hostilities, agreed to Eleftherios Venizelos ' proposal and accepted the Bulgarian request for armistice as this had been communicated through Romania.

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.

Constantine had altogether more colourful plans.

Justinian also had Anthemius and Isidore demolish and replace the original Church of the Holy Apostles built by Constantine with a new church under the same dedication.

Constans ’ brother, Constantine II, soon complained that he had not received the amount of territory that was his due, stemming from his position as the eldest of Constantine ’ s sons.

Annoyed that Constans had received Thrace and Macedonia after the death of Dalmatius, Constantine demanded that Constans hand over the African provinces, which, in order to maintain a fragile peace, he agreed to do.

Constantine soon complained that he had not received the amount of territory that was his due, stemming from his position as the eldest of Constantine ’ s sons.

Annoyed that Constans had received Thrace and Macedonia after the death of Dalmatius, Constantine demanded that Constans hand over the African provinces, which, in order to maintain a fragile peace, he agreed to do.

Additional complications also arose when Constans came of age, and Constantine, who had grown used to dominating his younger brother, would not relinquish the guardianship.

Kenneth's son Constantine died in 876, probably killed fighting against a Viking army which had come north from Northumbria in 874.

If he had been in exile, Constantine may have returned to Pictland where his cousin Donald II became king.

Another son had died at Brunanburh, and, according to John of Worcester, Amlaíb mac Gofraid was married to a daughter of Constantine.

It is possible that Constantine had other children, but like the name of his wife, or wives, this has not been recorded.

For example in the mid 350 ’ s the city of Jerusalem was hit with drastic food shortages at which point church historians Sozomen and Theodoret reported “ Cyril secretly sold sacramental ornaments of the church and a valuable holy robe, fashioned with gold thread that the emperor Constantine had once donated for the bishop to wear when he performed the rite of Baptism ”.

Eusebius claims, in his Life of Constantine, that the site of the Church had originally been a Christian place of veneration, but that Hadrian had deliberately covered these Christian sites with earth, and built his own temple on top, due to his hatred for Christianity.