Knights of St Catharine of Mount Sinai, an ancient military order, instituted for the protection of pilgrims going to pay their devotion to the body of St Catharine, a virgin of Alexandria distinguished for her learning, who is said to have suffered martyrdom under Maximin. The body of the martyr was discovered on Mount Sinai; and an order of knighthood was instituted in 1063, the members of which bound 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 by which the saint had suffered, namely, a half wheel armed with spikes, and traversed with a sword stained with blood.

St Catharine at Sienna, Fraternity of, a religious and charitable society, instituted in that city in honour of St Catharine, a saint famous for her revelations, and for her supposed marriage with Jesus Christ, whose wedding-ring is preserved as a valuable relic.