Schaff, Philip. History of the Christian Church (The Complete Eight Volumes in One). Amazon Kindle Edition, 2014.
Volume 2, Ante-Nicene Christianity A.D. 100-325, “Chapter 4. Organization and Discipline of the Church” Loc. 13792-14769 (part 10).
§55. The Councils of Elvira, Arles, and Ancyra.
Schaff notes a number of reasons councils were convened. In general, they were to discuss and deal with views questioning historical orthodoxy (Schaff 2014, Loc. 14516). Among these, the councils at Elvira, Arles, and Ancyra, at the start of the fourth century, receive special attention. These had an influence on future councils. Schaff observes they had no particular doctrinal question but did discuss polity (Schaff 2014, Loc. 14523).
Elvira, convened in 306 in Spain, considered types of immorality which were a concern to the church (Schaff 2014, Loc. 14523). The canons of this council sought to preserve purity within the church. Among other things, marriage outside the christian faith was prohibited and those who had denied the faith under persecution were not admitted back to communion (Schaff 2014, Loc. 14530).
Arles, in 314, was called by Constantine in response to the Donatist controversy (Schaff 2014, Loc. 14545). Donatus was excommunicated. Those of his movement fell from favor with the government. The official acts of the clergy were to be considered valid, even though the individual performing the aciton was defrocked.
Ancyra, probably also in 314, was convened to deal with the aftermath of Diocletian’s persecution (Schaff 2014, Loc. 14552). Priests who had caved to pressure in the persecution and had repented retained their dignity but were no longer to preach or engage in priestly functions.