Remembering Nicaea presents the first complete English translation of Anonymous Cyzicenus's Ecclesiastical History, the fullest surviving account of the Council of Nicaea (325 CE). The introduction features new arguments for the dating of the text, a discussion of Anonymous Cyzicenus's sources and their modification, and an evaluation of the larger purpose of the Ecclesiastical History. Appendixes include the text of the Byzantine epistolary supplement found in all manuscripts, the Pinakes, testimony about the work from the ninth-century patriarch of Constantinople, Photius, and the prefatory letter to the 1599 critical edition.