The three texts edited here belong to the second period of the acculturation of the Slavia Orthodoxa, after the mission of SS. Cyril and Methodius to Morava, the death of St. Methodius and the expulsion of his disciples from there in 886. They all stem from the greatest and most influential center of acculturation of the Orthodox Slavs before the advent of Slavic monks on Mt. Athos, that of Pliska and Preslav with its no less that 17 monasteries and one ore more well appointed libraries, which provided the Greek originals for wide-ranging translation and compilation projects, as well as the Slavic originals for reproduction and dissemination.

The first of them belongs to one of the most prolific authors of the period, Constantine the Younger, first bishop of Preslav (after 907), a disciple of SS. Cyril and Methodius. His work comprises original liturgical texts (all incorporating acrostics: Office for St. Methodius, Canon for St. Michael, Canons in the Triodion perhaps also Stichera in the Festal Menaion), probably also translated texts in the latter two liturgical books, and translated homilies (Four Homilies Against The Arians by St. Athanasius of Alexandria, dated 906). Whether his are also the translation of the Historia ecclesiastica et mystica contemplatio by Patriarch Germanos I of Constantinople and the compilation of the Istorikii, a brief survey of chronology from Adam to Emperor Leo IV (912), is not clear. His Gospel Homiliary is a compilation of exegetical homilies by St. John Chrysostom and St. Cyricl of Alexandria on the Gospel lessons for all Sundays of the ecclesiastical year, except Easter Sunday. Its Prologue is an original text, which expounds the year, except Easter Sunday. Its Prologue is an original text, which expounds the year, except Easter Sunday. Its Prologue is an original text, which expounds the aims and teh circumstances of the compilation and requests for it the Lord's blessing; it consists of [1] a title, [2] an Alphabet Prayer of 36 verses with [3] a doxology of four verses, and [4] a colophon.

The treatise On the Letters has been long ascribed to a monk named Hrabår, but the ascription was acknowledged to be unsubstantiated as early as 1859. The work is in part dependent on Greek grammatical and historical treatises [4-6, 9-10], but largely an original text [t-3, 7-8, 11-15]. In it, an anonymous author explains the features and teh history of the Glagolitic alphabet [1-7] and the Bible translations written in it [8-13], argues their greater holiness by comparison to the Greek [13], as well as the greater familiarity of their history to all Slavs [14], dates their introduction [14], and offers praise to the Lord for His gift to the Slavs [15].

The text On the Script has not before been recognised as a text separate from the treatise On the Letters, but merely as an excerpt version of it.

The three texts were written in Glagolitic. The first (P), to be dated no later than 893, i.e. 30 years after the introduction of the Glagolitic alphabet, has a transmission based on what must be the autograph, because it includes the author's marginal notes for a specific occasion of delivery. Its reconstruction, consequently, may aspire to restitute that autograph. The second (L) and the third(S), to be dated before ca. 919, have a transmission based on three different Glagolitic antigraphs, two of which are related to each other, while the third (S) is independent of either, related merely to the same Greek source. In that case, the reconstruction cannot pretend to restitute an author's text, not to mention his autograph, but must resign itself to constitute the earliest attainable text, both of the former and of the latter (which can be shown to have served as the starting point for the composition of the treatise).

What makes the conjunction of these three texts so important, as Kuev had sensed, are their heuristic properties, both in the historical and in the textological respect. (1) They present three complementary views of the original Glagolitic alphabet, expresssed at teh same place and over a time of less than half a century. (2) The texts are transmitted in multiple transcriptions into Cyrillic, which offer insight both into the subsequent development of the Slavic alphabets and into details of the comprehension and the reproduction of Glagolitic MSS. (3) The relation of the transcriptions to a limited number of Glagolitic antigraphs, with a limited life span, in conjunction with indications in the texts they transmit, makes it possible to date and localise them with a fairly high degree of reliability and to evaluate the performance of their makers with a higher degree of precision than before. (4)The very multiplicity of these transcriptions relateds them intimately to the process of elimination of the Glagolitic script and the concomitant creation of new Cyrillic archetypes of Chruch Slavic texts, and thanks to them this process can be surveyed at least in some of its fundamental aspects. Finally, (5) the fact that the transmitted texts are so well documented by MS witnesses, and (6) that they attest both types of tradition (open and closed) as well as various forms of contamination of the text, practically predestines these thre texts to serve as exempla for textological analysis and reconstruction.