EUCHOLOGION (Εὐχολόγιον). - As the name suggests, it is a collection of ecclesiastical prayers. This liturgical book contains the prayers recited by the priest and the deacon during the offices of Vespers and Orthros (Matins and Lauds), the text of the three eucharistic liturgies, the rites of the Sacraments, of funerals for the different categories of persons and of monastic professions, the blessings and consecrations of persons and of objects of worship, the formulas of blessings and prayers for the spiritual and temporal needs of the faithful, etc. G. Goor calls it Rituale, Manuale, Sacerdotale Ecclesiae Graecae. It is a book venerable above all others for its antiquity and for its importance.

(Id. Vatican Library)
The oldest manuscript Eucologies are the following: Codex Graecus Barberinus S. Marc. N. III, 55 (77), now Vat. gr. 366, of the 8th-9th century; the Codex of Bishop Porphyrius, once N. CCXXVI of the Imperial Library of St. Petersburg, of the 9th-10th century, which some date back to the end of the 8th century; Cod. Sin. N. 957 of the 9th-10th century; Cod. Sin. N. 958 and Cod. Cryptof. Γβ'Χ of the 10th century; Cod. Sebastjanov, once N. 15 (1474) of the Rumyantsev Museum (Moscow), of the 10th-11th century. From the 11th century onward, the manuscripts of the Eucologion are more numerous. Cf. Al. Dmitrievskij, Opisanie liturghievskich rakopisei chronijachchichija v' bibliotekach Pravoslavnogo Bostoka, vol. II, Εὐχολόγια, Kiev 1901; Ant. Rocchi, Codices Cryptenses seu Abbotiae Cryptae Ferratae in Tusculano, Rome 1884; Pl. de Meester, Rituale-Benedicionale Bizantino, Rome 1930, pp. IX-XVII; M. I. Orlov, Liturghija sv. Vasilija Velikogo, St. Petersburg 1909, pp. X-XVIII. The Slavonic versions are later (Orlov, op. cit., pp. XXX-XLVII), while euchological elements are found in Georgian, Syriac and Arabic manuscripts of the 10th-11th century. The first editions of the Greek text of the Eucologion appeared in Venice (1526, 1544, 1550, 1553, 1560 at Cristoforo Zanetti's; 1566 at Andrea Giuliani's, etc.). The hieromonk Theophylact corrected the later editions and added some prayers, and subsequently the Eucologion was subjected to various revisions and emendations. The first edition of the catechetical [parts] was printed in Rome in the year 1754 by order of Benedict XIV, who first had the 82 sessions of the Commission instituted by Innocent X and continued under Urban VIII and his successors summarized. The Roman edition of 1873 is a reprint of the preceding one. In these two Roman editions the rite of the consecration of a church is missing. Moreover, no edition contains the abundant elements of Byzantine euchology scattered through the manuscripts. A large part of this material is found in the works of G. Goar and of A. Dimitrievskij as well as in separate liturgical monographs printed in Greece and in Russia. Nic. Pan. Papadopulo enriched his edition of the Eucologion, published in Athens in 1927, with rites and prayers pertaining to these sources.
From the complete Eucologion (Εὐχολόγιον τὸ Μέγα) described above one must distinguish the small Eucologion (Εὐχολόγιον τὸ Μικρόν), which contains only the liturgy of St. John Chrysostom, the sacramental rites, some Epistles and Gospels and a few prayers. The collection of the most used blessings formed the ritual called the Hagiasmatarion and Benedictional, while the ritual elements most used by the bishop are found in the Archieratikon, and the prayers recited by the deacon gave rise to the Diakonikon (Διακονικός). The most authoritative commentary on the Eucologion and a Latin translation of the texts are found in the magisterial work of G. Goar, Εὐχολόγιον, sive Rituale Graecorum. With the exception of the Sacraments, the rites of the Greek Eucologion and of the Slavonic Trebnik, which is its equivalent, are commented on with the help of the manuscripts in the op. cit. of de Meester.
Piscido de Meester