The practice of perpetual prayer was inaugurated by the archimandrite Alexander (died about 430), the founder of the monastic Acoemetae or "vigil-keepers".
Laus perennis was imported to Western Europe at St. Maurice's Abbey in Agaunum, where it was carried on, day and night, by several choirs, or turmae, who succeeded each other in the recitation of the divine office, so that prayer went on without cessation.
Called the Akoimetoi ("Sleepless Ones"), these monks prayed "a monastic round of twenty-four offices to fill every hour".
[1] The inauguration of laus perennis at Agaunum c. 515 was the occasion of a solemn ceremony, and of a sermon by St. Avitus which survives.
[3] The various Roman Catholic orders of nuns dedicated to the perpetual adoration of the Blessed Sacrament may be seen as a modern variation on this theme, because in addition to the usual complete daily liturgical celebration of the Eucharist and Divine Office, these monastic communities also observe a perpetual adoration of the Blessed Sacrament, which usually involves having at least two members of the monastic community always being present in prayerful, silent contemplation of the Blessed Sacrament (i.e., a consecrated Host) exposed to view in a monstrance on the altar of the principal chapel.