| Constantine | |
| Emperor of the Romans | |
| Succession: | Byzantine co-emperor |
| Moretext: | (with Theophilos) |
| Predecessor: | Theophilos |
| Successor: | Theophilos |
| Reign: | 830s |
| Birth Date: | 820s or 830s |
| Death Date: | before 836 |
| Burial Place: | Church of the Holy Apostles |
| Father: | Theophilos |
| Mother: | Theodora |
| Dynasty: | Amorian dynasty |
Constantine (Greek, Modern (1453-);: Κωνσταντῖνος, 820s or 830s – before 836) was an infant prince of the Amorian dynasty who briefly ruled as co-emperor of the Byzantine Empire sometime in the 830s, alongside his father Theophilos. Most information about Constantine's short life and titular reign is unclear, although it is known that he was born sometime in the 820s or 830s and was installed as co-emperor soon after his birth. He died sometime before 836, possibly after falling into a palace cistern.
Constantine was born to the Byzantine Emperor Theophilos and his wife Empress Theodora. The coinage issued under Theophilos suggests that Constantine was their firstborn son, and he was perhaps their eldest child, although there remains a possibility that he was any one of their first four. He had five sisters: Thekla, Anna, Anastasia, Pulcheria, and Maria. Constantine and his family belonged to the Amorian dynasty, which had ruled the Byzantine Empire since the accession of Constantine's paternal grandfather Michael II to the imperial throne in 820. Unusually, Theophilos defied standard naming conventions, as his son was not named after Michael II; instead, Theophilos chose the name Constantine, which the Byzantinist Judith Herrin explains could be an homage to Constantine the Great or a hope that the prince would continue the iconoclastic religious policies of previous emperors named Constantine.
As Theophilos had succeeded Michael II on 2 October 829, Constantine was heir to his father's throne and was crowned co-emperor a short time after his birth. He appears as such on the coinage issued under his father, albeit addressed as despot (not a formal title, but an honorific interchangeable with, i.e. emperor) on gold coins, but with no title at all on bronze ones. He died shortly afterwards, still in his infancy. The British historian Philip Grierson used the inscription on Constantine's coffin, which read Greek, Ancient (to 1453);: λαρνάκιον, meaning "little coffin", as evidence to support the claim that Constantine died young.
There is little clarity as to the dates of his birth, coronation and death. In the Prosopography of the Middle Byzantine Period, its authors, including the Byzantinist Ralph-Johannes Lilie, state that Constantine's birth date could possibly be during the 820s and his death date to be before 831. The historian Lynda Garland argues that Constantine was born in 834 and died when he was two years old, assuming that he was crowned immediately after his birth. Herrin also agrees with this birth date. In any case, only one emperor is mentioned in the Latin: [[De Ceremoniis]], a 10th-century book describing Byzantine courtly protocol and history written by Constantine VII, for 831; Constantine is also missing on coins minted in 831/32 and 832/33; this could mean he was only raised to co-emperor in 833. The historian Warren Treadgold states that Constantine died around 835; he must have died by 836, since in that year Theophilos was recorded as being without a male heir (Constantine's younger brother Michael III would be born in 840), a situation Theophilos attempted to rectify by marrying his infant daughter Maria to general Alexios Mosele, who shortly before this (possibly as early as 831) had been promoted to Latin: [[Caesar (title)|caesar]] (heir to the throne).
According to the Latin: [[Theophanes Continuatus]], a collection of writings likely written in the 10th century, Constantine died by drowning in a cistern at the Palace of Blachernae after escaping the care of his nurse. Constantine's saddened father constructed gardens on the spot of his son's death, although the Prosopography of the Middle Byzantine Period points out that this story may actually refer to a son of another emperor, not Constantine. His parents buried him in a sarcophagus made of Thessalian marble in the Church of the Holy Apostles. In the Latin: De Ceremoniis, Constantine VII wrote that Constantine's coffin lay beside that of his sister Maria.