In the 4th century AD, the emperor, absolute monarch though he was, ruled by consensus, and consensus could only maintained at the price of compromise. Thus, emperors who failed to understand the principle of clemency not only violated the common code of proper conduct, they also threatened the foundations of their rule.

Valentinian I and Valens were largely indifferent to the diversity of religious belief in their worlds, and both tried primarily to maintain the status quo by privileging Christianity without attacking paganism. Valens differed from his brother, primarily because of the different circumstances in which the two operated.

The new strength of Christianity in the 4th century opened an alternative avenue to power through the bishops, who successfully challenged the authority of the emperor and his officials. The rise of powerful bishops also helped fractionalize the church and pulled emperors into ecclesiastical power struggles. Thus, the Homoians were the dominant church in the east when Valens attained the throne, and they gained their dominance at the expense of the Homoiousians. In upholding the council of Constantinople (360) by suppressing the Homoiousians, Valens was carrying on the task initiated by Constantius II of defending the official state church. Valens was also willing to entrust ecclesiastical affairs to a small though powerful group of Homoian clerics.

Jovian’s rhetoric of concord was kept alive by his successor, Valentinian – who was a Nicene, but did not favor Nicenes any more than any other Christian faction. Valentinian maintained a detached indifference to the doctrinal debates of his day, a luxury he was allowed by the much calmer atmosphere in the churches of the west. Valens, by contrast, was forced to clean up the mess Julian had created by forcibly applying the doctrines of the council of Constantinople (360), which had imposed Homoian Christianity in the east and deposed some of the most important Homoiousian bishops there. Having done this, Valens was able to operate with much the same indifference as his brother during the middle years of his reign, when he aimed primarily at achieving peace and concord in the church. After the death of Athanasius in 373, Valens began to exert considerable force in order to achieve the illusory end of unifying the church around the Homoian creed. The violence Valens wreaked in Egypt constituted something of a turning point in his relationship with the church. Only at the end of his reign did Valens turn to the scorching persecutions that have left him with the reputation of a religious persecutor; by 376, Valens’s name became synonymous with heresy and religious violence.

Like his brother, Valens desired harmony in the church. Unlike his brother, he had not learned that belief cannot be dictated by force. Valens failed to understand that ecclesiastical loyalties were a local matter and could not be controlled from on high. Many 4th–century emperors attacked religious dissenters, but very few suffered a catastrophic fate like Valens’s to prove, in the eyes of contemporaries, that they had provoked the wrath of the divine.

Valens’s disaster at Adrianople guaranteed the victory of the Nicene faction in the long-standing battle over the person of Christ. Without the destruction of the Arian emperor Valens and without the political and military chaos that it provoked, there probably would never have been this solidarity effect under emperor Theodosius I – the solidification of a formerly divided church around the Nicaena fides. Thus, Valens helped the church become what it is, however paradoxical this may sound.