Marie-Théodor Ratisbonne, N.D.S., (December 28, 1802 – January 10, 1884) was a French Jewish convert to the Catholic Church, who became a priest and missionary and who later founded the Congregation of Our Lady of Sion. He was the brother of Marie-Alphonse Ratisbonne, who joined him in this effort. He was baptized in 1826, at which time he added the name Marie (Mary) to his given name, and was ordained as a priest in 1830.
Théodor Ratisbonne published a biography of St. Bernard of Clairvaux, A Life of St. Bernard, in 1841. During a visit to Rome the following year, this work drew the admiration of Pope Gregory XVI, for which the Pope made him a Knight of the Order of St. Sylvester in recognition of his contribution to the Catholic faith.
Bernard of Clairvaux (Latin: Bernardus Claraevallensis), O.Cist (1090 – 20 August 1153) was a French abbot and the primary reformer of the Cistercian order.
After the Christian defeat at the Siege of Edessa, the pope commissioned Bernard to preach the Second Crusade. The last years of Bernard's life were saddened by the failure of the crusaders, the entire responsibility for which was thrown upon him. Bernard died at the age of 63, after 40 years as a monk.
In the year 1128 AD, Bernard participated in the Council of Troyes. It was at this council that Bernard traced the outlines of the Rule of the Knights Templar who soon became the ideal of Christian nobility. Around this time, he praised them in his Liber ad milites templi de laude novae militiae.
A Life of Saint Bernard (1841) Ratisbonne,
https://books.google.com/books?id=pNk8AAAAIAAJ&pg=PA134&lpg=PA134&dq=Med...
https://books.google.com/books?id=UOoDAAAAQAAJ&pg=PR19&lpg=PR19&dq=A+Lif...(1841)+Ratisbonne,&source=bl&ots=8jDYAEHuoR&sig=dJbJ8UwDGyePWyuGDlLTLbqiD8Y&hl=en&sa=X&ved=0ahUKEwi55oTluNDPAhWDoD4KHSNoArcQ6AEIRjAJ#v=onepage&q=A%20Life%20of%20Saint%20Bernard%20(1841)%20Ratisbonne%2C&f=false