Augustine speaks of the Moor Rogatus, bishop of Cartenna in Mauritania Cæsariensis, in his ninety-third epistle, to Vincentius, c. iii. 11. We learn from the eighty-seventh epistle, to Emeritus, sec. 10, that the followers of Rogatus called the other Donatists Firmiani, because they had been subjected to much cruelty at their hands under the authority of Firmus.