Etymology, nature and synonyms.  The word vigil is from the Latin vigilare, to keep awake, to watch, because in old times the night before any great event, religious or worldly, was spent in watching.  Thus, the night prior to ordination to the priesthood, the night prior to a great battle, was spent in watching before the altar.  Hence, the word vigil came to mean the prayers said during the time of watching or waking, preparatory to the great event.  It signified, too, the fast accompanying the watching, and lastly it came to mean the liturgical office of Mass and Breviary fixed for the time of vigilance.  In the Roman Church it was sometimes called the nocturn or night office.  The Greeks call the vigil profesta, the time before the feast.

The custom existed among the pagans, almost universally, before the time of Christ.  The Jews practised this ancient night prayer, as the scripture in several places shows, "in noctibus extollite manus vestras in sancta" (Psalm 133).  Our Saviour sanctified this use by His example, and the early Christians were, on account of these night assemblies, the objects of fear and dread, of admiration and of hatred.  Organised vigils lasted till the thirteenth century in some countries, but owing to abuses and discord they became not a source of edification, but the occasion and cause of grave scandals, and were forbidden gradually and universally.  The Church now retains for the faithful one congregational vigil, the vigil of Christmas.  Formerly, it was customary to observe a fast on a day or night of a vigil, but that custom was suppressed sometimes, or fell into disuse.  Vigil fasts are now few.  Almost the only relic of the vigil now remaining is the Mass and Office.

When were vigils held?  In the early ages they were held only on Saturday nights and on nights preceding great solemnities or the festivals of the Martyrs.  The early converts, if they had been pagans, knew few or no prayer formulae, and very little of the psalms was learned by them even in their Christian practice.  But Jews who became Christians knew psalms and hymns and prayers.  So that in the early Christian vigils, there was no attempt made at reciting the Divine Office, and the custom of such recitation was not introduced until about 220 A.D. and was not obligatory (Duchesne, Christian Worship, Chap.  VIII.).

It is difficult to speak with certainty about the hour of beginning or the hour of ending these vigil services.  Some think that the first nocturn was said about 9 p.m.  Lauds was said before sunrise and hence was called Laudes-matutinae.  But “after the middle of the ninth century, we gather from contemporary documents, that the office of vigils was, as a whole, regularly constituted and well known” (Baudot, p.64).  These vigils were held in cenacles or upper rooms of houses.  During the days of persecution these meetings were not infrequent and were held secretly in crypts, catacombs, private houses and at martyrs’ tombs.  In times of peace they were held everywhere, in churches, monasteries, castles.