The main subject of letters sent by pope Gregory the Great to Africa is the activity of the Donatists. The pope appeals severely to bishops and secular authorities to suppress schism. There is little evidence of the Donatists' survival after the conference of Carthage in the year 411. Therefore certain researchers (e.g. R.A. Markus) claim that Gregory wrongly estimated the situation, applying the old name to other phenomena, such as the autonomy of African episcopate. It was also possible that the Donatists had achieved some modus vivendi with the Catholics under the reign of Arian Vandals. Some 5th and 6th century sources indicate that the Donatists were considered as opponents by both Catholics and Arians. On the other hand, as it happens, there are sometimes no information about the Donatists where we would expect them. Hence, it may be difficult to estimate clearly the value of information provided by Gregory the Great, but it is definitely not true that nothing is known about the Donatists in the times between Augustine and Gregory.