GERBERT, MARTIN VON HORNAU. - Benedictine, b. at Horn on the Neckar (Württemberg) on 12 Aug. 1720, d. in the abbey of St. Blasien (Black Forest) on 13 March 1793. Having entered the said abbey at the age of 16 (1736) and been ordained a priest (1744), he taught philosophy and theology there for ten years; and, being at the same time assigned to the library, he had the opportunity to deepen his knowledge of sacred and profane history and especially of medieval music and liturgy. He completed his education with travels in Germany, Italy and France, collecting a great many documents (1759-62).
Elected prince-abbot in 1764, he showed a father's care for the monks and provided them with new constitutions; when a fire destroyed the monastery in 1768, he rebuilt it and endowed it with a beautiful church, also transforming it into a true academy of scholars and establishing in it what was called the first German institute of historical research: there he in fact directed the compilation and publication of the Germania Sacra (v.). Most devoted to the Holy See, he sought to act as mediator between episcopalism and the papacy, and fought effectively against Josephinism in the Austrian territories placed under his jurisdiction.
He wrote a great deal: besides the Iter Alemanicum; Accedit Italicum et Gallicum (St. Blasien 1765) and the Historia Silvae Nigrae Ordinis S. Benedicti coloniae (3 vols., ibid. 1783-1784), in which he speaks of the numerous Benedictine monasteries spread through the Black Forest from the 7th to the 18th century and also of the various episcopal sees and the principal families of the territory; he published on music: De cantu et musica sacra a prima Ecclesiae aetate usque ad praesens tempus (2 vols., ibid. 1774), followed by: Scriptores ecclesiastici de musica sacra potissimum ex variis Italiae, Galliae et Germaniae codicibus manuscriptis collecti (3 vols., ibid. 1784; anastatic reproduction, Milan 1931); on the liturgy: Vetus liturgia Alemanica (2 vols., ibid. 1776); Monumenta veteris liturgiae Alemanicae (2 vols., ibid. 1777-79); on theology: his Principia theologiae exegeticae, dogmaticae, symbolicae, mysticae, canonicae, moralis, sacramentariae, liturgicae (in as many volumes, ibid. 1757-60) form a truly complete ecclesiastical encyclopedia. His copious correspondence, predominantly historical-scientific, with a complete bibliography and detailed introductions, was edited by G. Pfeilschifter (3 vols., so far I, Karlsruhe 1931; II, ibid. 1934).
