Military Orders of St. Michael
(1) A Bavarian Order, founded in 1721 by Elector Joseph Clemens of Cologne, Duke of Bavaria, and confirmed by Maximilian Joseph, King of Bavaria, 11 September 1808. Pius VII, 5 Feb. 1802 granted to priests decorated with this order all the privileges of domestic prelates. Under Louis I it was made an order of merit (1837), and under Otto I was reorganized (1887).
(2) An order founded in 1469 by Louis XI, the chief military order of France until the institution of the Knights of the Holy Ghost, after which the two together formed the ordres du roi, the reception of the cross of the former being made a condition to membership in the other. After the Revolution the order was revived, in 1816, as a distinction to be conferred on those who had accomplished notable work in art or science or who had performed extraordinary services for the state. In 1825 there was a solemn reception into the ordres du roi, which did not, however, survive the Revolution of 1830.
(3) Knights of St. Michael’s Wing, founded in the Cistercian monastery of Alcobaza about 1171, by Alfonzo I, King of Portugal, in commemoration of victory over the Moors, in which, according to tradition, he was assisted by St. Michael in person. The knights were placed under the jurisdiction of Abbot of Alcobaza and were pledged to recite the same prayers as the Cistercian lay brothers. The order was in existence but a short time.
FLORENCE RUDGE McGAHAN (Catholic Encyclopedia)