Origin and youth Louis Caesar Constantine de Rohan-Guemène belonged to the
House of Rohan, an ancient and powerful family of the nobility of Brittany which dates back to the xi th century. Son of
Charles III de Rohan, cousin of
Armand-Gaston-Maximilien de Rohan and his second wife, Charlotte-Elisabeth de Cochefilet (1657–1719), he is the fourteenth and last child of the couple. His brother
Armand-Jules de Rohan-Guémené, future
archbishop of Reims, had chosen the ecclesiastical state. Louis-César-Constantin de Rohan embraced at first the career of arms. He was first a
Knight of Malta before entering the navy as a naval officer. He was promoted to
capitaine de vaisseau in 1720.
Career in the Church In 1732, at the age of 35, he and entered upon an ecclesiastical career, being named canon and grand provost of
Strasbourg. In 1734 he was appointed commendatory Abbot of
Lyre Abbey, near
Evreux, then first
chaplain to the King in 1748,
commendatory Abbot of Saint-Epvre the following year, and
prelate-commander of the Order of the Holy Spirit in 1753. On the death in 1756 of his uncle,
Armand de Rohan-Soubise, he was appointed to succeed him as
Bishop of Strasbourg, a post which carried with it the title of
Prince of the
Holy Roman Empire (though most of
the principality's territory situated on the left bank of the
Rhine had been annexed by
France in the late 17th century) and likewise the title of Count of Alsace. However, he was not made
Grand Almoner of France, unlike other members of the
Rohan family who became bishops of
Strasbourg. He was created cardinal by
Pope Clement XIII at the Consistory of 23 November 1761. However, he did not take part in the
conclave of 1769, summoned upon the death of Pope Clement XIII, nor in the
conclave of 1774-1775, summoned upon the death of
Pope Clement XIV. His cousin and successor as Cardinal Prince-
Bishop of Strasbourg,
Louis-René-Édouard de Rohan-Guémené, would be compromised in the
Affair of the Diamond Necklace. == Coat of arms ==