He was born as the son of Philippe Jules Mancini, 8th Duke of Nevers and Diane Gabrielle Damas (1656-1715), he was the great-nephew of both King Louis XIV of France's mistress, Madame de Montespan, and his first chief minister, Cardinal Mazarin.

In 1709 he married Maria Anna Spinola (1678–1718), daughter of Juan Bautista Spinola, Marchese of Vergagna and Marie Françoise du Bois.

Their only child was the academician Louis Jules Mancini, the final Duke of Nevers.

He could not inherit the title of Duke of Nevers from his father in 1707, because the duchy had not been properly registered at the Parlement of Paris.

In 1720 he received letters of confirmation for the duchy of Nevers from the Parlement.