A very old term applied to night Offices. Tertullian speaks of nocturnal gatherings (Ad. Uxor., II, iv); St. Cyprian, of the nocturnal hours, "nulla sint horis nocturnis precum damna, nulla orationum pigra et ignava dispendia" (De orat., xxix). In the life of Melania the Younger is found the expression "nocturnæ horæ", "nocturna tempora" (Anal. Bolland., VIII, 1889, pp. 49 sq.). In these passages the term signifies night prayer in general and seems synonymous with the word vigiliæ. It is not accurate, then, to assume that the present division of Matins into three Nocturns represents three distinct Offices recited during the night in the early ages of the Church. Durandus of Mende (Rationale, III, n. 17) and others who follow him assert that the early Christians rose thrice in the night to pray; hence the present division into three Nocturns (cf. Beleth, Rupert, and other authors cited in the bibliography). Some early Christian writers speak of three vigils in the night, as Methodius or St. Jerome (Methodius, "Symposion", V, ii, in P. G., XVIII, 100); but the first was evening prayer, or prayer at nightfall, corresponding practically to our Vespers of Complines; the second, midnight prayer, specifically called Vigil; the third, a prayer at dawn, corresponding to the Office of Lauds. As a matter of fact the Office of the Vigils, and consequently of the Nocturns, was a single Office, recited without interruption at midnight. All the old texts alluding to this Office (see , Vigil) testify to this. Moreover, it does not seem practical to assume that anyone, considering the length of the Office in those days, could have risen to pray at three different times during the night, besides joining in the two Offices of eventide and dawn.

It was during the second period, probably in the fourth century, that to break the monotony of this long night prayer the custom of dividing it into three parts was introduced. Cassian in speaking of the solemn Vigils mentions three divisions of this Office (De cœ;nob. instit., III, viii, in P. L., XLIX, 144). We have here, we think, the origin of the Nocturns; or at least it is the earliest mention of them we possess. In the "Peregrinatio ad loca sancta", the Office of the Vigils, either for week-days or for Sundays, is an uninterrupted one, and shows no evidence of any division (cf. Cabrol, "Etude sur La Peregrinatio Sylviæ", Paris, 1895, pp. 37 and 53). A little later St. Benedict speaks with greater detail of this division of the Vigils into two Nocturns for ordinary days, and three for Sundays and feast-days with six psalms and lessons for the first two Nocturns, three canticles and lessons for the third; this is exactly the structure of the Nocturns in the Benedictine Office to-day, and practically in the Roman Office (Regula, ix, x, xi). The very expression "Nocturn", to signify the night Office, is used by him twice (xv, xvi). He also uses the term Nocturna laus in speaking of the Office of the Vigils. The proof which E. Warren tries to draw from the "Antiphonary of Bangor" to show that in the Celtic Church, according to a custom older than the Benedictino-Roman practice, there were three separate Nocturns of Vigils, is based on a confusion of the three Offices, "Initium noctis", "Nocturna", and "Matutina", which are not the three Nocturns, but the Office of Eventide, of the Vigil, and of Lauds (cf. The Tablet, 16 Dec., 1893, p. 972; and Bäumer-Biron, infra, I, 263, 264).

The division of the Vigils into two or three Nocturns in the Roman Church dates back at least to the fifth century. We may conjecture that St. Benedict, who, in the composition of the monastic cursus, follows the arrangement of the Roman Office so closely, must have been inspired equally by the Roman customs in the composition of his Office. Whatever doubt there may be as to priority, it is certain that the Roman system bears a strong analogy to that of the Nocturns in the Benedictine Office even at the present time, and the differences subsisting are almost entirely the result of transformations or additions, which the Roman Office has been subjected to in the course of time. On Sundays and feast-days there are three Nocturns, as in the Benedictine Office. Each Nocturn comprises three psalms, and the first Nocturn of Sunday has three groups of four psalms each. The ferial days have only one Nocturn consisting of twelve psalms; each Nocturn has, as usual, three lessons. For the variations which have occurred in the course of time in the composition of the Nocturns, and for the different usages see . These different usages are recorded by Dom Marténe. For the terms, "Nocturnales Libri", "Nocturnæ", see Du Cange, "Glossarium infimæ latinitatis", s. vv.

See ; Vigil; Cassian, De cœ;nob. instit. II, x; Beleth, Rationale, xx; Liber Diurnus, P. L., CV, 71; Durandus of Mende, Rationale, III, n. 7; Rupert, De div. oficiis, I, x; Marténe, De antiquis Monach. rit., IV, 4 sq.; Zaccaria, Onomasticon, 50, 51; Bäumer-Biron, Histoire du Bréviare, I (Paris, 1905), 74 sq., 78, 99, 263, 358-361, etc.

F. Cabrol.