The Order of the Most Holy Savior (Latin: Ordo sanctissimi Salvatoris), abbreviated as O.Ss.S., and informally known as the Brigittine or Bridgettine Order is a monastic religious order of Augustinian nuns, Religious Sisters and monks founded by Saint Bridget of Sweden (Birgitta) in 1344, and approved by Pope Urban V in 1370. There are today several different branches of Bridgettines.
The original Bridgettine Order was open to both men and women, and was dedicated to devotion to the Passion of Jesus Christ. It was a “double order” each monastery having attached to it a small community of monks to act as chaplains, but under the government of the abbess.
St Bridget's Rule stipulated:
the number of choir nuns shall not exceed sixty, with four lay sisters; the priests shall be thirteen, according to the number of the thirteen apostles, of whom Paul the thirteenth was not the least in toil; then there must be four deacons, who also may be priests if they will, and they are the figure of the four principal Doctors, Ambrose, Augustine, Gregory and Jerome, then eight lay brothers, who with their labors shall minister necessaries to the clerics, therefore counting three-score sisters, thirteen priests, four deacons, and the eight servitors, the number of persons will be the same as the thirteen Apostles and the seventy two-disciples.