The most important are:
1. In 313, against the lapsi, and on discipline;
2. In 341, by pope Julius I and the Eastern bishops, in favor of Athanasius;
3. In 352, by Liberius, for the same object;
4. In 358, against the emperor Constans and the heretics;
5. In 364, at which were present deputies from the Council of Lampsacus;
6. In 366, at which the Macedonians adopted the Nicene Creed;
7. In 367, to examine into the charge of adultery preferred against the pope Damasus;
8. In 369, by Damasus, at which Ursinus and Valera were condemned;
9. In 372, at which Auxentius, bishop of Milan, was excommunicated;
10. In 374, by Damasus, condemning Apollinaris;
11. In 375, condemning Lucius, bishop of Alexandria;
12. In 376, against the Apollinarists and others;
13. In 380, fourth of Damasus, against the Sabellians, Arians, etc.;
14. In 400, against the Donatists;
15. In 430, against Nestorius;
16. In 444, against the Manichees;
17. In 774, giving Charlemagne power to elect the Roman pontiff, and to invest all bishops;
18. In 963, deposing pope John XII and appointing Leo VIII;
19. In 964, deposing Leo VIII;
20. In 964, restoring Leo VIII and deposing Benedict V, etc. (See LATERAN); (See VATICAN).