Constantine V ruled from 741 to 775, was the most successful soldier-emperor of his century, and is remembered chiefly through the abuse of the writers who defeated his religious policy.
Constantine V was born in 718, in the year his father held Constantinople against the Umayyad siege, and ruled from 741 until his death on campaign in 775. By any military measure he was the most successful emperor of the eighth century.
He fought the Bulgars for most of his reign and generally beat them, campaigned across the Taurus against the caliphate, repopulated a capital emptied by plague, and handed on a stable throne to his son.
He also pushed iconoclasm further than his father, called a church council to declare images heretical, and persecuted the monasteries that resisted. The tradition that eventually won gave him the name Kopronymos, and it is the name that stuck.
He was born in Constantinople in 718 and crowned co-emperor as an infant in 720, so he had no life before the purple. His mother was Maria, and his father the general who had taken the throne the year before he was born.
He was on campaign early. At Akroinon in 740 he fought beside his father in the battle that destroyed the last great Umayyad raiding army in Anatolia, and he succeeded to the throne the following year.
His accession was immediately challenged. Artabasdos, his brother-in-law and commander of the Opsikian troops, seized Constantinople while Constantine was in Asia and held it for two years with the support of the image-venerating party. Constantine retook the city in 743 and had the usurper blinded.
Nothing written about him is neutral. The sources are the work of the iconophile monastic tradition — Theophanes above all — writing after the policy he championed had been condemned, and they are less a portrait than a prosecution.
The prosecution nonetheless has to concede the record. He is described as personally brave, obsessively attentive to logistics and fortification, and popular with the army and with the population of the capital he repopulated and re-watered. Some of his measures were remembered gratefully for generations, and a century later crowds prayed at his tomb during a Bulgar invasion.
The hostile detail is largely about his manner and his tastes: the nickname Kaballinos, mocking his interest in horses and stables; the accusations of coarseness; the story of the baptismal font that produced Kopronymos. These belong to the vocabulary of vilification rather than to biography, and they are worth naming precisely so a reader can see what kind of evidence they are.
The Bulgar wars ran through his whole reign — nine campaigns by the usual count, combining army and fleet, and aimed at the Bulgar heartland rather than at defending Thrace. His victory at Anchialos in 763 was the most complete, and the pressure he sustained kept the Bulgar khanate in crisis for two decades.
In the east he went over to the offensive for the first time in a century, raiding across the Taurus and taking Germanikeia and Theodosiopolis in the 740s and 750s while the caliphate changed dynasty. He resettled captured Christian populations in Thrace, which served both the frontier and the depopulated Balkans.
The army he did this with was partly his own creation. He built the tagmata — professional regiments based near the capital, loyal to the emperor rather than to a provincial commander — which gave the throne a striking force and, not incidentally, an insurance policy against the kind of provincial revolt that had raised his own father.
In 754 he called a council at Hieria, attended by more than three hundred bishops and without the Pope or the eastern patriarchs, which declared the veneration of images heretical. That gave the policy a conciliar authority it had lacked under Leo III.
Enforcement went much further than his father had taken it, and it fell hardest on the monasteries, which were the strongest centres of resistance. Monks were publicly humiliated, forced to marry, imprisoned and in some cases killed; the patriarch Constantine II was deposed, paraded and executed. Monastic property was confiscated.
The Second Council of Nicaea condemned Hieria in 787, twelve years after his death, and iconoclasm was finally abandoned in 843. Everything preserved about his theology comes through the refutations written by the winners, so his own arguments survive only as quotations chosen to be answered.
He left the empire militarily stronger and financially sounder than he found it, with a professional central army, a working frontier, a repopulated capital and an undisputed succession — and a religious policy that would be condemned as heresy within a generation.
The condemnation shaped the record so thoroughly that his reputation had to be reconstructed by modern historians from what his enemies could not deny. It is the clearest case in this archive of a reign whose evidence is entirely in the hands of the opposition.
His dynasty ended with his grandson, deposed and blinded by his own mother Irene, who restored the images. What outlasted him was the tagmata, the Bulgar frontier he had held, and the eastern offensive posture that the tenth century would carry to Antioch.