Constantine VI was Byzantine Emperor reigning from 780 to 797 AD. Today on 20th July in the year 792, Constantine VI defeated by Kardam of Bulgaria at the Battle of Marcellae.
At 10 years of age, Constantine succeeded his father, Leo IV, under the guardianship of his mother, Irene. When Constantine reached sixteen, the age at which he could rule in his own right, his mother, Irene, did not relinquish the executive authority she held. In 790, with military support, Constantine finally came to actual power.
The Battle of Marcellae took place in 792 at Macellae, near the modern town of Karnobat in southwestern Bulgaria. The battle was between the forces of the Byzantine Empire, led by Constantine VI, and those of Bulgaria under Kardam. The Byzantines were defeated and forced to withdraw to Constantinople.
On 19 April 797, Constantine was captured, blinded, and imprisoned by the supporters of his mother, who had organized a conspiracy, leaving Irene to be crowned as first Empress regnant of Constantinople.
The above shown gold Solidus was issued under his reign from Constantinople mint. The obverse of the coin shows the busts of Constantine VI (on left), wearing crown and chlamys, globus cruciger in the right hand, and Irene (on right), wearing loros and crown with four pinnacles, cruciform scepter in left hand; cross above between their heads, pellet in the center. The reverse of a coin depicts Leo III, Constantine V and Leo IV seated facing, each wearing crown and chlamys.
Image Source: Heritage Auctions