The passage is taken from the letter of Augustine to Fabiola, a noble Roman who offered hospitality and help to Antoninus. Antoninus, a young lector of the Church of Hippo was ordained as the bishop of Fussala when the original candidate withdrew (see [399]). Antoninus was later accused of several crimes. Augustine and his colleagues tried to make him step down, but he appealed to Rome. Fussala used to be a Donatist see, so the date of the event is between AD 411 (the conference of Carthage) and AD 419 (the recourse of Antoninus to Rome).
The status of the presbyter in question is unclear: he was a notarius in the monastery of Augustine. He came from some place other than Hippo. The presbyterial ordination was the first clerical grade he received. We do not know the names of the clerics mentioned in the passage, but both of them were ordained by Antoninus (see ep. 20*.5, [400], from which the information in this paragraph has been taken).