Whether it was the very limited availability of Greek texts, or lack of interest in learning ancient Greek in Western Europe, or both, knowledge of the Greek classics in their original language was very limited in Europe during the late Middle Ages.
"Not before the fifteenth century were there large collections of Greek manuscripts assembled in the West, and only from the sixteenth century on were they used by a substantial number of Western scholars and other interested parties. The greater portion of the Greek inventory of the Dominican Library in Basel, the Laurentiana in Florence, the Marciana in Venice, the Vaticana in Rome, the Hapsburg Hofbibliothek in Vienna, and the Bibliothèque du Roi in Paris was first brought together through the combined efforts of Greek emigrants, Latin Humanists, and bibliophile princes. Yet ancient Greek book collections were not inaccessible to the Latin Middle Ages. Greek monasteries, none of which could have been completely without books, flourished in Rome from the seventh to the eleventh century. Grottaferrata has preserved parts of its ancient hoard of Greek books even up to the present day.
"There were populous Latin districts in Constantinople during the high Middle Ages, and in this period a great number of Italian scholars lived in the Christian metropolis on the Bosporus and made use of the rare-book libraries of the city. Moses of Bergamo was one of these scholarly Italians in twelfth-century Constantinople; he is the first Westerner known to have collected Greek manuscripts in great volume. If his own testimony is true, then the hunt for Greek manuscripts began two centuries before Guarino of Verona and Giovanni Aurispa.
"The Greek libraries of southern Italy were even closer to the Latins than those in Constantinople. Casole in Apulia, Carbone in the Basilicata, Stilo in Calabria, and Messina in Sicily had the most notable monastic libraries of the Italo-Greeks; the Cathedral Library of Rossano is still in possession of its cimelia, the famous sixth-century Greek purple evangelary ('Codex purpureus Rossanensis'), which was not 'rediscovered' there by scholars until 1879 and which recalls the significance of southern Italy for the transmission of Greek texts.
"Not before the manuscript research of recent years has the astonishing volume and the high quality (manuscripts of the classics!) of Italo-Greek book production and transmission come to light. Manuscript by manuscript, a 'translatio studii' from Byzantium to the West appears, whose line of textual transmission threads its way directly from the Macedonian Renaissance in tenth-century Constantinople, to the court library of the Norman and Hohenstaufen rulers of southern Italy, to the papal library of 1300; the Italian Renaissance picked up this thread as its starting point.
"This hoard of Greek books first appears in 1295 at the end of a catalogue of the papal library:
'Item Dyonisius super celesticam [!] Ierarchicam [!] in greco. Item Simplicius super phisicam Aristotilis . . .'
"With the exception of Dionysius the Areopagite (characteristically placed at the beginning of the list) and one other work, the twenty-three volumes all contain works of natural science and philosophy—a remarkable collection for the papacy (ed. A. Pelzer, Addenda et emendanda ad Francisci Ehrle Historiae Bibliothecae Romanorum Pontificum ... tomum 1 [Rome 1947], pp. 23 f).
"A catalogue of the papal library from 1311 lists the same stock of Greek books:
'tem libri, qui sequuntur scripti in greco: primo scripsimus comentum Procli Permenidem Platonis 'And' et est in papiro . . . .'
"There have been several changes. In all there are now thirty-three Greek codices; ed. F. Ehrle, Historia Bibliothecae Romanorum Pontificum tum Bonifatianae tum Avenionensis (Rome 1890), I, 95-99. In nineteen of these books one finds this remarkable 'And', for which Ehrle provides the hardly convincing resolution antiquus.
"We learn from an inventory of 1327 that the thirty-three Greek codices were kept in two crates; ed. Pelzer, Addenda et emendanda, p. 34. In 1339 they (all of them?) are found in a single crate together with Hebrew books (ibid., p.64); in 1369 there are still seven Greek books in the papal library (cf. Ehrle, Historia Bibliothecae, pp. 376 [no. 1183], 398 [no. 1512], 429 [no. 2007]. The popes obviously managed to carelessly lose their small but fine Greek collection during their Avignon adventures.
"The enigma of the notation And in the catalogue of 1311 has been solved by August Pelzer in a striking way (Addenda et emendanda, pp. 92 f.): it is to be resolved Andegavensis = Anjou! -that is, these books came to the papal library 'from Anjou.' When did the house of Anjou have cause and opportunity to present the papacy with a collection of Greek books? Pelzer answers: after the battle near Benevento (1266), when Charles of Anjou, whom the papacy had summoned to southern Italy, had disposed of the hated Hohenstaufen King Manfred. Thus the core of the Greek collection of the Norman-Staufer court library came into the possession of the papacy in 1266 in a similar way to that by which the Heidelberg Bibliotheca Palatina did in 1623.
"Codicological research has confirmed Pelzer's brilliant conclusions. Nine of the thirty-three Greek books of the 1311 catalogue have now again been identified, and the findings demonstrate clearly that this could not have been a casual acquisition by the popes or by Anjou, nor was it plunder from the conquest of Constantinople in 1204.; rather the collection came from the court in Constantinople to the court in Palermo around the middle of the twelfth century:
'Ces volumes sont de magnifiques produits des ateliers constantinopolitains au moment de la renaissance scientifique et philosophique des IXe et Xe siècles" ('These volumes are the magnificent products of the ateliers in Constantinople at the moment of the scientific and philosophical renaissance of the ninth and tenth centuries;' (P. Canart, "Le livre grec,' p. 149).
"Almost half of all known scientific 'classical manuscripts' of the Byzantine Renaissance of the ninth/tenth century have been preserved via the Norman-Staufer court library (G. Derenzini, 'All origine della traduzione di opere scientifiche classiche: vicende di testi et di codici tra Bisanzio e Palermo,' Physis 18 , 87-103). Thus the history of the Greek court library in the West extends back into the twelfth century, and the Greek collections in Renaissance court libraries in the West were then not altogether without precedents.
"In the outstanding monastic and cathedral libraries of the Middle Ages, there were, however, at most only scattered Greek manuscripts. The Abbey of St. Martin in Tours possessed, at least in fragments, a Greek papyrus codex from Egypt, which contained a homily of Ephraem Syrus on 'Fair Joseph.' An illuminated Greek copy of the XPICΤΙΑΝΙΚΗ ΤΟΠΟΓΡΑΦΙΑ of Cosmas Indicopleustes has been traced to the collection of the early medieval Cathedral Library in York. Reichenau had a precious Greek Psalter from the eighth to the sixteenth century. The Abbey of St. Denis tended the splendid uncial manuscript of the works of Dionysius the Areopagite which Louis the Pious had obtained from Constantinople; various other Greek manuscripts were added in the high and late Middle Ages. In the monastery of St. Simeon, established in the Porta Nigra in Trier, there was a Greek lectionary of the tenth/eleventh century. In the midst of the Investiture Controversy, the wealthy and ostentatious canons of St. Gereon in Cologne procured a magnificent Greek Psalter, which was written and illuminated around 1077 in a scriptorium closely connected with the Greek emperor. The first illumination, by a Greek artist, shows Ο ΑΓΙΟC ΜΑΡΤΥC ΤΟΥ ΧΡΙCΤΟΥ ΓΕΡΕΩΝ.
"Μany other large libraries of the Middle Ages also had their Greek showpieces to exhibit. Occasionally, the Latin West also produced manuscripts entirely in Greek. In the ninth century, as Montfaucon has noted, Sedulius Scottus was capable of writing a Greek Psalter with odes.
"From the Ottonian period on, Greco-Italian southern Italy offered the opportunity to obtain scribes who were acquainted with the Greek alphabet. A lectionary written in 1021 by an Italo-Greek Εν χόρα Φραγκίας κάστρο δε Κoλoνίας (= Cologne?) later made its way to St. Denis. In England even Western scribes ventured to produce various Greek minuscule manuscripts. According to Μ.R. James, the Greek Psalter of Cambridge, Emmanuel College III. 3. 22 is of English origin.
"In the thirteenth century, Bishop Robert Grosseteste commissioned a large-scale Corpus Dionysiacum in Greek minuscules. Grosseteste, his students, and his assistants brought together, by means of purchasing and copying, a significant collection of Greek manuscripts in England, so that it is true, at least for this country, that interest in Greek books had already arisen in the late Middle Ages; to be sure, it was a narrow circle until Humanism created a broader audience for the purely Greek book.
"The typical medieval form of the Greek codex was the bilingual manuscript. It was an inheritance from late antiquity and the Middle Ages in part made good use of it. The Mediterranean cultural symbiosis of the late Roman Empire had brought forth many such bilinguals-Latino-Greek and Greco-Latin. The most famous examples of late antique Latino-Greek editions are the remnants of the bilingual Vergil codices, recovered from the Egyptian sand; thus far, no less than nine such bilinguals of the champion of the imperial Roman cause have been brought to light. During Justinian's time, it was certainly still possible to write codices in both imperial languages in Constantinople; the Florentine digest codex ('Codex Pisanus,' soon after 533) bears impressive witness to this fact. It seems, however, that the Byzantine Empire of the medieval period proper no longer fostered bilingual editions of Roman authors, and—if southern Italy is excluded—produced no Latino-Greek manuscripts at all.
"A Greco-Latin Homer, the counterpart of a Latino-Greek Vergil, apparently did not exist in late antiquity. The West was interested in Christian bilinguals, in Greco-Latin editions of portions of the Bible; a Greco-Latin anthology of canon law may have also existed during late antiquity, at least in one copy.
"The Latin Middle Ages carried on the tradition of assorted scriptural bilinguals: the Psalter, Gospels, Pauline epistles, and Acts of the Apostles (in fact those four books of the Bible whose comparative study Ambrogio Traversari recommended for self-instruction in Greek!). It would have been easy for the bilingual tradition of the Acts of the Apostles to have disappeared, as other bilingual scriptural texts must have: the tradition has only two witnesses-the 'Codex Bezae' in Cambridge and the 'Codex Laudianus' in Oxford.
"The Carolingian period transmitted only the Psalter, Gospels, and Pauline epistles, to some extent in the new interlinear bilingual form, which was especially cultivated by the Irish.
"In the Ottonian period, the bilingual tradition of the Pauline epistles dies out. The fragmentary 'Codex Waldeccensis' (saec. X ex. ) completes the circle of this bilingual tradition of the Middle Ages, in which the beginning and end are joined; for this bilingual manuscript, the last of the Pauline epistles known from the Middle Ages, is an exact copy of the earliest manuscript—the 'Codex Claromontanus.'
"The production of bilingual texts of the Gospels is extraordinarily rare in the high and late Middle Ages. Yet a bilingual edition of the Apocalypse curiously surfaces at that period. The Greco-Latin Psalter reached the age of Humanism, however, in an unbroken tradition. This Greco-Latin text outlasted all else because it was the text with which the Latin Middle Ages was doubtless most intimately familiar and was thus better suited than any other text to introduce the Latins to a basic study of Greek. This tradition of the Greco-Latin Psalter manuscripts, which span the entire Middle Ages, from the Cod. Verona I (saec. VI- VII) to the Cod. Plut. XVII 13 of the Biblioteca Laurenziana (which was "erst wenige Jahre alt, als in Florenz das große Unionskonzil begann" ["only a few years old as the great Union Council began in Florence"]), and to the great trilingual (Hebreo-Greco-Latin) Psalter produced for Duke Federigo of Urbino in Florence in 1473, presents scarcely touched material for the further investigation of Greek studies in the Latin Middle Ages.
"The Greek text is presented in various manners in these Psalters: in Greek script (generally majuscule) or in Roman transcription; the Greek and Latin texts on facing pages, in parallel columns, or arranged interlinearly. The base text (left page, left column, or principal line in interlinear versions) is generally Greek. The Psalters in which the Greek text is presented only in Roman transcription must have originally served primarily liturgical purposes: Greek liturgica were always written in the Roman alphabet in the West, since they were to be read or sung aloud and were not intended to be studied. On the other hand, manuscripts with the Greek text written in Greek script were textbooks or even showpieces. The possibilities for combination are numerous and the distinctions between them fluid: even such an obvious example of a textbook as the St. Gall psalterium quadrupartitum presented the Greek text only in Roman transcription. In general, each of the numerous bilingual Psalters of the Middle Ages requires its own particular historico-philological interpretation.
"The other Greco-Latin books of the Middle Ages may be regarded as offshoots from the main trunk of bilingual biblical texts: in the sixth century, bilinguals of the first four ecumenical councils by Dionysius Exiguus; in the eleventh century, Gregory's Dialogi; in the thirteenth century, the liturgical and polemical bilinguals of Abbot Nicholas-Nectarius of Otranto. The Dominican mission in the 'Orient' continued this latter tradition and produced its controversial theological tracts in bilingual editions ('Bartholomaeus, Contra Graecos; Buonaccorsi, Thesaurus veritatis fidei). Leontius Pilatus' translations of Homer and Euripides for the early Florentine Humanists were designed as interlinear bilinguals.
"Finally, one must not forget the striking bilingualism of the imperial correspondence from Constantinople, of which a number of splendid examples from the twelfth to the fifteenth centuries have been preserved in Italian archives. When the corpus of manuscripts has finally been fully catalogued, the history of the Greco-Latin bilinguals will open one of the most informative perspectives on the ever-shifting interest in Greek texts that has perished through the ages" (Walter Berschin, "Valuation and Knowledge of Greek," Greek Letters and the Latin Middle Ages. From Jerome to Nicholas of Cusa. Transl. by Jerold C. Frakes ).