PSALTER (PSALTERIUM). — This name derives from φάκτωρ, *psalterium*, a stringed musical instrument, and by analogy, the collection of hymns to be sung to the *psalterium*, the biblical book containing the Psalms (cf. V. PSALMS), which later became a liturgical book and a manual of private devotion.
I. THE PSALTER IN THE WESTERN CHURCH
The psalter occupies a place of preeminence in the religious life of antiquity and the Middle Ages and was soon extracted from the Bible to become a separate book of prayers, both liturgical and private. In antiquity and for much of the Middle Ages, the psalter was almost the sole manual of devotion for the laity (cf., for example, the characteristic passage in the letter of Paula and Eustochium to Marcella: *PL* 22, 491). It was also used as a textbook for reading exercises (various psalters are bound with the alphabet), whence the term *psalteratus* as a synonym for *litteratus*. For clerics and monks, the psalter has always been and remains the preeminent book of prayer. In the early Middle Ages, clerics, before being ordained, were required to memorize it; this explains the widespread custom among many of reciting it in its entirety, in addition to the portion assigned to the office, once or twice daily. At Farfa and Cluny, the last hours of a dying person were accompanied by the recitation of the psalter; elsewhere, it was sung or recited during the vigils of the dead, especially those of bishops and abbots.Partial or complete recitation of the psalter was prescribed by Penitentials (cf., for example, those of Egbert of York [735–66], Aligarius of Cambrai [817–31], and Burchard of Worms [1000–25]) as a substitute for severe corporal penances imposed for certain sins. The psalter was also used for the so-called *sortes sanctorum*, divinatory practices prohibited by the Carolingian Capitularies and by Burchard’s Penitential, which involved seeking answers to any question by opening the book and reading the first verse of a psalm.
1. **Types of Psalters.** — We shall not discuss here its contents (for which cf. V. PSALMS), but only the psalter as a separate book, of which there are two main categories: biblical psalters and liturgical psalters, each subdivided into various types.
A) **Biblical Psalters.** — The most common type consists of an excerpt from the Bible containing the 150 psalms (*psalterium non fractum*) in one of the pre-Hieronymian versions (the Milanese psalter used in the Ambrosian rite, the Gallican psalter in the ancient Gallican rite, the Spanish psalter in the Mozarabic rite, the Veronese psalter, the Roman psalter in the Roman rite; cf. V. LATIN VERSIONS OF THE BIBLE) or in one of the three Hieronymian versions: the Roman (384, a simple revision of the Roman psalter based on the Septuagint; it is debated whether this is the psalter still used in the basilica of St. Peter), the Gallican (ca. 389; initially used in the liturgy of the Gauls, as attested by a manuscript of the 8th century: Paris, Bibl. Nat., lat. 11, mid-8th century), which comprises as many as 20 folios (cf. A. Wilmart, *Codices Reginenses Latini*, I, Vatican City 1937, p. 26).
B) **Liturgical Psalters.** — The classic type of liturgical psalter, the *psalterium per ferias* or *psalterium feriale*, contains the 150 psalms arranged according to the various canonical hours for each day of the week, along with the *Ordinarium Divini Officii*, i.e., the invitatories, hymns, antiphons, chapters, responsories, and collects. Alongside this complete type, there are other less comprehensive versions. It is not uncommon to find manuscript psalters with invitatories, antiphons, and collects noted in the margins, often only with their incipits; after the psalms, biblical canticles for Lauds are usually included, and in the case of monastic psalters, also for the third Nocturn. Various hymns, the *Te Deum*, the *Gloria in excelsis*, the Apostles’ and Athanasian Creeds, the Litany of the Saints, and penitential psalms, etc., may also be included. Depending on their content, the following types can be distinguished: 1) *hymn psalters*, containing a variable number of hymns for weekdays and feasts; 2) *Books of Hours psalters*, with private prayers recited after the office (cf. V. BOOKS OF HOURS); 3) *diurnal psalters*, containing antiphons, chapters, hymns, and collects for the day; 4) *antiphonaries*, containing the parts to be sung; 5) *ritual psalters*, containing prayers and rubrics for the administration of the Sacraments. In addition to liturgical psalters, the medieval period saw the popularity of the *Psalter of the Virgin* (from the 12th century onward), a poetic or prose composition of 150 strophes, and the *Psalter of St. Jerome*, which included a certain number of verses taken from the psalms without any logical connection.
2. **Criteria for Dating and Identification.** — Among liturgical manuscripts, psalters, which are generally anonymous, present some of the greatest difficulties for dating and identifying the church to which they belonged. In addition to paleographic evidence, one must consider any local elements present in the calendar, the Litany of the Saints, hymns dedicated to certain saints, the series of antiphons and biblical canticles, or the Office of the Dead.
3. **Illumination.** — Like other liturgical books, the psalter received special care from scribes and illuminators, resulting in a rich series of psalters executed with exquisite artistic taste, ranging from those transcribed in fine uncial and semi-uncial script on purple parchment (5th–7th centuries and Carolingian era) to those finely illuminated from the 16th century onward. Notable examples include the 6th-century silver-and-gold uncial psalter of St. Germain (cf. Le Roux [V. BIBLICA.], II, pp. 110–111); the 8th-century uncial psalter of Stuttgart (A. Dold, in *Römische Quartalschrift*, 1934); the 9th-century psalter of the Abbey of Hautvillers, known as the Utrecht Psalter (cf. E. T. De Wald, *The Illustrations of the Utrecht Psalter*, London-Leipzig 1932); the 10th-century psalter of Egbert of Trier at Cividale, executed between 977 and 993 (cf. H. V. Sauerland-H. Haseloff, *Der Psalter Erzbischof Egberts von Trier. Codex Gertrudianus* [in Cividale, Trier 1901]); the 13th-century psalter of St. Louis (cf. Le Roux, II, pp. 101–105); the ca. 1490 psalter of Charles VIII (Le Roux, II, pp. 57–58); the 1542 psalter of Paul III (L. Dorez, *Le psautier de Paul III*, Paris 1909), etc. Some of the earliest printed editions are also notable for their harmony. The most ornate parts of manuscript psalters are: 1) the calendar, where depictions of the months and the zodiac are often reproduced; 2) certain pages preceding the psalms; and 3) the portion reserved for the text of the psalms themselves. From the 8th century onward, pages preceding the psalms prominently feature David and Christ in Majesty or even on the Cross; David, with his musical instrument, is sometimes accompanied by other psalmists playing with him. From the 12th century onward, scenes related to Christ take on greater development; in the 13th–14th centuries, these pages are decorated with entire cycles of scenes drawn from the Old and New Testaments. Various systems were used to illustrate the text of the psalms: each psalm is adorned with scenes related to its content, or the psalter is divided into three or five books, with the first psalm in each division being illuminated (in the first case, Psalms 1, 51, 101; in the second, Psalms 1, 41, 72, 89, 106); at other times, the first psalm of each feria is adorned (1, 26, 38, 51, 52, 68, 80, 97, 101, 109), though not always does the figure relate to the content of the psalm. In addition to fully or partially illuminated pages, there is a wide range of large and small initials and marginal decorations executed with rare skill and imaginative flair.