De duodecim abusivis saeculi

De duodecim abusivis saeculi ("On the Twelve Abuses of the World") is a Hiberno-Latin treatise on social and political morality written by an anonymous Irish author between 630 and 700. During the Middle Ages the work was very popular throughout Europe.
Background.
The work was first propagated throughout Europe by Irish missionaries in the 8th century. It had been ascribed at different times to canonical and popular authors: Saint Patrick, Saint Augustine, but traditionally to Saint Cyprian. It was not until 1909 that Siegmund Hellmann () established it as the work of an anonymous Irish author of the 7th century. Since then its author is conventionally known as Pseudo-Cyprian.
Duodecim abusivis saeculi.
"De duodecim" condemns the following twelve abuses:
Influence.
Hellmann points out the extensive influence of the work upon Carolingian writings, such as the mirrors for princes, and later political literature.
There is some direct evidence for the text's popularity in tenth-century England. Bishop Æthelwold of Winchester is known to have donated a copy to the Peterborough house. Ælfric of Eynsham drew on a version included in Abbo of Fleury's "Collectio canonum" for his Old English treatise "De octo vitiis et de duodecim abusivis gradus", in which the section on the "rex iniquus" was translated whole.