Library Eusebius of Caesarea Life of Constantine
Book 2, Chapter 66: That he also adjusted the Controversies which had arisen in Africa.
Finding, then, that the whole of Africa was pervaded by an intolerable spirit of mad folly, through the influence of those who with heedless frivolity had presumed to rend the religion of the people into diverse sects; I was anxious to check this disorder, and could discover no other remedy equal to the occasion, except in sending some of yourselves to aid in restoring mutual harmony among the disputants, after I had removed that common enemy of mankind who had interposed his lawless sentence for the prohibition of your holy synods.
English translation by Ernest Cushing Richardson, in Nicene and Post-Nicene Fathers, Series II, Vol. I (eds. Philip Schaff and Henry Wace; Buffalo: Christian Literature Publishing Co., 1890). Public domain. Digital text via New Advent Church Fathers.