Charles III de Rohan was born on 30 September 1655, the son of Charles II de Rohan, Duc de Montbazon, Prince de Guemene and his wife, Jeanne Armande von Schomberg.
He succeeded his father as Duc de Montbazon, Prince de Guemene 3 July 1699.
He married firstly, 1678, Marie Anne d'Albert, daughter of Louis Charles d'Albert, Duc de Luynes; she died 20 August 1679.
He married secondly, 2 December 1679, Charlotte Elisabeth de Cochefilet, the daughter of Charles de Cochefilet, Comte de Viauineux. She was born 1657, and died 24 December 1719, having had 13 children.
Charlotte de Rohan, born 20 December 1680, married 1) 5 February 1717, Antoine de Colins, Comte de Mortagne (died 24 March 1720); 2), 1729, Jean de Crequi, Comte de Canaples, she died 20 September 1733;
Louis Henri de Rohan, born in December 1681, died as a child on 22 January 1689;
Francois Armand de Rohan, born 4 December 1682, called the Prince de Montbazon, died before his father 26 June 1717. He married 28 June 1698, Louis Julie de La Tour-d'Auvergne, (born 26 November 1679, died 21 November 1750), daughter of Godefroi Maurice de La Tour-d'Auvergne, Duc de Bouillon, and had issue
Charles Jules de Rohan, born in 1700, died young 5 December 1703;
Anne Therese de Rohan, born 15 October 1684, Abbess of Jouarre, died 2 November 1738;
Louis Charles Casimir de Rohan, born 6 January 1686, a priest, entitled Comte de Rochefort, died 1748/1749;
Hercule Meriadec de Rohan, born 13 November 1688, succeeded his father;
Marie Anne Benigne de Rohan, born in August 1690, twin with the following, Abbess of Panthemont, Paris, died 5 February 1743;
Marie Anne de Rohan, born in August 1690, twin with the preceding, a nun at Jouarre, died 18 August 1711;
Angelique Eleonore de Rohan, born 14 August 1691, Abbess of Preaux and Marquette, died 1753;
Charles de Rohan, born 7 August 1693, Prince de Rochefort;
Armand Jules de Rohan, born 10 February 1695, Archbishop of Rheims, died 28 August 1762 at Zabern;
Charlotte Julie de Rohan, born 1 March 1696, a nun at Preaux, died 3 April 1756;
Louis Cesar Constantine, born 24 March 1697, Cardinal, Bishop of Strasbourg, died 11 March 1779.