In the sixth century, Saint Benedict was one of many abbots who wrote a Rule for his monks. He had established monasteries at Subiaco and Monte Cassino in Italy. These monasteries were destroyed by the Barbarian invasions but a few manuscripts of his Rule survived and were carried by refugees to other monasteries in Rome, North Italy, and Gaul. In the course of two centuries the use of the Rule spread and it was due to the influence of Charlemagne that it acquired a monopoly in the west. In this way, Saint Benedict came to be considered the founder of the Black Monks of the Middle Ages, called from that time the "Order of Saint Benedict".

Each independent house of the Order is a separate family ruled by an abbot and has its own novitiate. The work of each house is centred on the Divine Office or public prayer, recited or sung in choir at intervals throughout the day. This work is common to and characteristic of all Benedictine houses whether of monks or nuns.

A choir monk, after his profession, may be ordained priest once he has completed two years of philosophy and four years of theology, but this need not always be the case, as can be seen in Saint Benedict himself.

Through the centuries, the Order has spread to all the continents. Although monasteries everywhere base their life on Saint Benedict's Rule, local conditions made it inevitable that certain modifications would be found necessary. Saint Benedict, in fact, makes provision for this in his Rule and the abbot has the right to adapt the timetable, clothing, food and drink to local conditions. These modifications in time were drawn up as "Constitutions" and were approved by the Holy See.