The Pseudo-Nonnus Commentaries on Sermons IV, V, XXXIX and XLIII by Gregory of Nazianzos collect and explain most of the references to Hellenic learning and mythology made therein. They reflect the views (and level of education) of a tolerant but committed Eastern Christian of the early sixth century A.D., and excited much interest, both in the Byzantine world, and, after they were printed, in the West. Later commentators and scholiasts on St. Gregory made much use of the work, as did other writers and compilers of encyclopaedias. The edition is based upon an investigation of almost all of the 150 known manuscripts, and provides a text which is largely supported by the Syriac and Armenian versions. These are of early date. Recent collations of their texts are included in the apparatus criticus. The Introduction defines the relationship between the versions and the Greek text, the latter's recensions and the history of its tradition, with detailed stemmata. It surveys and updates previous and contemporary studies through the extent of the evidence at its disposal and the generous help of others. A brief list of sources accompanies the text and apparatus criticus, and an Appendix, Indices Nominum and an Index Codicum are included.