Returning to France, which was then ruled by
Napoleon Bonaparte, Jules continued in his zealous loyalty to the exiled royal family. In 1804, a year after his sister's death, Jules was implicated in the conspiracy of
Cadoudal and
Pichegru to assassinate Bonaparte, and was imprisoned until 1813. After the restoration of the
Bourbons, he was rewarded with various honours and positions. He held various offices, received from the Pope his title of "Prince," in 1820, and in 1823, King
Louis XVIII made him ambassador to Great Britain. A year later, his mother's former friend ascended the throne as King
Charles X. Polignac's political sympathies did not alter, and he was one of the most conspicuous
ultra-royalists during the Restoration era. At the time, it was rumoured that Polignac supported ultra-royalist policies because he thought he was receiving inspiration from the
Virgin Mary. There is little historical evidence for this story, however. There is no mention of such motivation in Polignac's personal memoirs or in the memoirs of the Restoration court. On 8 August 1829,
Charles X appointed him to the ministry of foreign affairs and in the following November, Polignac became president of the council, effectively the most powerful politician in France. Critics of the king’s government saw Polignac’s rise as a step towards overthrowing the constitution. Polignac, with other ministers, was held responsible for the decision to issue the
Four Ordinances, which were the immediate cause of the
revolution of July 1830. Upon the outbreak of revolt, he fled, wandering for some time among the wilds of
Normandy before he was arrested at
Granville. At his trial before the Chamber of Peers, he was condemned and sentenced to 'perpetual' imprisonment at the château in
Ham. But he benefited by the amnesty of 1836, when his sentence was commuted to exile. During his captivity, he wrote
Considerations politiques (1832). Afterwards, he spent several years in exile in England before being permitted to re-enter France, on condition that he never again take up his abode in Paris. According to the
Legacies of British Slave-Ownership at the
University College London, de Polignac was awarded a payment as a slave trader in the aftermath of the
Slavery Abolition Act 1833 with the
Slave Compensation Act 1837. The British Government took out a £15 million loan (worth £ in ) with interest from
Nathan Mayer Rothschild and
Moses Montefiore, paid from the public budget (formally ending in 2015). de Polignac was associated with three different claims, he owned 628 slaves in
Saint Vincent and the Grenadines and received a £15,765 payment at the time (worth £ in ). Although a French subject, de Polignac had connections in the British Empire due to his Scottish wife, Barbara Campbell (1788–1819), daughter of Duncan Campbell of Ardnave. From his second marriage to Maria-Charlotte Parkyns, daughter of Lord Rancliffe, Jules de Polignac had fathered seven children, including Prince Ludovic de Polignac (1827–1904), a lieutenant-colonel in the French Army who participated in the colonization of
Algeria; Prince
Camille Armand Jules Marie de Polignac (1832–1913), a major-general in the
Confederate Army during the
American Civil War; and
Prince Edmond de Polignac (1834–1901), a composer, musical theorist and proponent of the
octatonic scale. Jules died at St. Germain in 1847 from the effects of his imprisonment. About one month prior, he had assumed the title of duc de Polignac upon the death of his older brother, Armand, who had died without children.
Comte Pierre de Polignac, later Prince Pierre, Duke of Valentinois (father of
Rainier III of Monaco and therefore an ancestor of the entire current princely family) is descended from a different and
cadet branch of the Polignac family, which has the comital rank only. Pierre was the youngest son, descended from the youngest son of the first Duke of Polignac. ==Ancestry==