'To abolish diverse malignant heresies') was a decretal and bull of Pope Lucius III, written at Verona and issued 4 November 1184.
The historical context for the issuing of Ad abolendam was papal reassertion of its authority in Europe following the Investiture Dispute with the Emperor, and its discovery of what has been called a 'legislative' means of doing so.
[3] The Third Lateran Council of 1179 had already resolved to prevent schisms of the kind that the Investiture Dispute had created, and decretals such as Ad abolendam were intended to enforce this;[4] Fisher has suggested that it was no coincidence that the decree followed the Peace of Constance of the previous year, at which the Emperor was in effect compelled to acknowledge defeat.
[1] For the enforcement of the measures demanded by the decretal, Lucius obligated all patriarchs, archbishops, and bishops to re-announce the excommunication on certain feasts and holidays.
They were to make bi- or triannual rounds[clarification needed] of their dioceses, visiting locations of suspicion and questioning the people about the existence of heresy.