Knights of St Catharine of Mount Sinai, an ancient military order, erected for the assistance and protection of pilgrims going to pay their devotion to the body of St Catharine, a virgin of Alexandria, distinguished for her learning, and said to have suffered martyrdom under Maximin. The body of the martyr having been discovered on Mount Sinai, caused a great concourse of pilgrims; and travelling being very dangerous, by reason of the Arabs, an order of knighthood was erected in 1063, on the model of that of the holy sepulchre, and under the patronage of St Catharine; the knights of which obliged themselves by oath to guard the body of the saint, keep the roads secure, observe the rule of St Basil, and obey their grand master. Their habit was white, and on it were represented the instruments of martyrdom whereby the saint had suffered; viz. a half wheel armed with spikes, and traversed with a sword stained with blood.

Fraternity of St Catharine at Sienna, a sort of religious society, instituted in that city in honour of St Catharine, a saint famous for her revelations, and for her marriage with Jesus Christ, whose wedding ring is still preserved as a valuable relic. This fraternity yearly endows a certain number of destitute virgins, and has the privilege of redeeming annually two criminals condemned for murder, and the same number of debtors, by paying their debts.