Bonacursus was a 12th-century Italian Cathar who converted to Catholicism and released a confessional report to the people of Milan exposing the nature of the Cathar heresy entitled "Manifestatio haeresis catharorum quam fecit Bonacursus" sometime between 1176 and 1190.[1] He also reported on the Pasagian heresy[2] as well as the Arnoldists.[3]