At the instance of Theodore Ascidas, and with the ostensible purpose of reuniting to the Church the Acephali, a sect of Monophysites, Justinian was induced to censure the "Three Chapters".
Facundus was in Constantinople when this censure was pronounced, and shortly after its publication he and several other western bishops refused to subscribe to the decree, alleging that it was an attack on the Council of Chalcedon, which had accepted at least the letter of Ibas to the Persian Maris.
The conduct of the pontiff and his acquiescence in the condemnation of the "Three Chapters" spurred Facundus to complete this work, which he entitled Pro Defensione Trium Capitulorum.
Because of the attitude of Vigilius in acceding to the emperor's insistence that he subscribe to the censure of the "Three Chapters", Facundus and many African bishops cut themselves off from communion with him.
This schism lasted for many years, and during that time Facundus wrote two other works at the request of his fellow-bishops, in response to reproaches of insubordination (Liber contra Mocianum Scholasticum and Epistola Fidei Catholicae in defensione trium capitulorum).