This article examines the textual criticism of the most influential Byzantine liturgical commentary, Historia Mystagogica Ecclesiastica (HME). In the current scholarship it is usually taken for granted that this commentary belongs to St. Germanus I of Constantinople. This view was substantiated in detail by R. Bornert in his book, Les commentaires byzantines... (Paris, 1966). My own study of all the oldest extant manuscripts of the HME has led me to the conclusion that Borner’s arguments are insuffi cient, and his typology of redactions of the HME is erroneous and therefore deserves to be revised. I have collated all the 10–12th-century manuscripts of the HME — as well as the early Latin and Slavonic translations of it, — and identifi ed the oldest redactions of the commentary. One of these should be considered to be the primary one, and I put forward the arguments in favor of the very redaction which is witnessed by the oldest manuscripts of the HME and which seems to have been the most widespread in the Middle Byzantine period. All the manuscripts of this primary redaction of the HME attribute its authorship to St. Basil the Great, but the commentary, undoubtedly, does not belong to him. It is a composition by a nameless author of the late 7th or of the first half of the 8th century, who comments on the Liturgy of St. Basil. Such a dating is supported by the presence of some specifi c liturgical and theological features in the HME (these will be studied further in the upcoming articles). Finally, I present my own critical edition of the primary redaction of the HME, accompanied by a new Russian translation.
