A work in four books, which, though purporting to be Charlemagne's composition, was only written at his request by another, possibly Alcuin or some Irish theologian at the Frankish court c.790-792,as a protest to be sent to Pope Adrian I. It is a theological treatise in which both the Iconoclastic council of 754 and its opponent the Seventh General Council of Nicaea, 787, are severely criticized, especially for their views on the use of images, and it had its origin in the fact that the decrees of the General Council had reached the Frankish bishops in a very faulty Latin version in which, among other errors, idolatry was approved.