The Letters appearing here in translation were written approximately between the years 410 and 420. This period in Augustine's life coincides with the ending of the long controversy with the Donatists and the spread of the Pelagian errors concerning nature and grace. When compared with earlier letters there is more emphasis in these letters on intellectual and doctrinal matters.
Perhaps the most important, and certainly the longest in this collection, (pp.141-190) is letter 185 addressed in 417 to the tribune Boniface. It gives a vivid description of the crimes committed by the Donatists against Catholics. Augustine writes: "Some (Catholics) had their eyes put out; one bishop had his hands and tongue cut off; some were massacred. I say nothing of the inhuman beatings, of the looting of homes in nightly raids, of fires set not only to private homes but even to churches; and into these flames some even cast the sacred books" (chapter 30).
The civil authorities eventually intervened in these disturbances and at times with coercive measures. Finally on January 30, 412 the Emperor Honorius made the profession of Donatism a criminal offense and ordered clerics and ministers of such heretics removed from the African soil which they had polluted by sacreligious rites. Though initially opposed to coercion, Augustine changed his view.