This is the “First Hour,” roughly at 7:00 A.M. (Recall that in the Roman system counting began at sunrise, approximately 6:00 A.M.). John Cassian mentions that this first hour was instituted to prevent the monks of Bethlehem from returning to bed between the end of Lauds and the hour of Terce. Prime is historically the most recent of the Little Hours, since Terce, Sext and None all seem to be of an earlier origin. We know that Prime was being prayed in the West at Lerins (modern France) by the end of the fifth century. The first mention of it is in a document by Saint Caesarius of Arles (+543 A. D.) in his Rule for Nuns, chapter 64. It seems to have taken a while for the Office of Prime to receive general acceptance in the West. By the time of Saint Benedict in the early 500s it does seem to have been an accepted office.
The little hour of Prime was officially dropped or suppressed in the liturgical reforms of Vatican II, but communities and individuals are still free to pray it, as do some of the Benedictine monasteries of the Solesmes Congregation, as well as the Abbey of Pluscarden in Scotland, part of the Subiaco Congregation, of which Christ in the Desert is a member. We pray the hymn of the Office of Prime at the beginning of our work meeting each morning, alternating it one day in Latin, the next day in English.