Lucien Bonaparte, Prince Français, 1st Prince of Canino and Musignano (21 May 1775 – 29 June 1840), born Luciano Buonaparte, was the third surviving son of Carlo Buonaparte and his wife Letizia Ramolino.

Lucien was a younger brother of Joseph and Napoleon Bonaparte, and an older brother of Elisa, Louis, Pauline, Caroline and Jérôme Bonaparte. Lucien held genuinely revolutionary views, which led to an often abrasive relationship with his brother Napoleon, who seized control of the French government in 1799, when Lucien was 24.

Lucien was born in Ajaccio, Corsica, in 1775, and was educated in mainland France. In 1769 the Corsican Republic had been conquered by French forces and annexed into France. Lucien's father Carlo Bonaparte had been a strong supporter of Corsican patriots under Pasquale Paoli, but later switched to become a supporter of French rule. Lucien returned to Corsica at the outbreak of the French Revolution in 1789 and became an outspoken speaker in the Jacobin Club at Ajaccio, where he renamed himself "Brutus". An ally of Maximilien Robespierre during the Reign of Terror, he was briefly imprisoned (at Aix - en - Provence) after the coup of 9 Thermidor.

As president of the Council of Five Hundred — which he removed to the suburban security of Saint - Cloud — Lucien Bonaparte's combination of bravado and disinformation was crucial to the coup d'état of 18 Brumaire (date based on the French Revolutionary Calendar) in which General Bonaparte overthrew the government of the Directory to replace it by the Consulate. Lucien mounted a horse and galvanized the grenadiers by pointing a sword at his brother and swearing to run him through if he ever betrayed the principles of Liberté, égalité, fraternité. The following day Lucien arranged for Napoleon's formal election as First Consul.

Napoleon made him Minister of the Interior under the Consulate, which enabled Lucien to falsify the results of the plebiscite but which brought him into competition with Joseph Fouché, the chief of police, who showed Napoleon a subversive pamphlet that was probably written by Lucien, and effected a breach between the brothers. Lucien was sent as ambassador to the court of Charles IV of Spain, (November, 1800), where his diplomatic talents won over the Bourbon royal family and, perhaps as importantly, the minister Manuel de Godoy.

Though he was a member of the Tribunat in 1802 and was made a senator of the First French Empire, Lucien came to oppose many of Napoleon's imperial ideas, particularly the marriage of convenience planned for him. In 1804, spurning imperial honors, he went into self imposed exile, living initially in Rome, where he bought the Villa Rufinella in Frascati. In 1810 he tried to emigrate to America but was captured en route by the British, and he then lived as a prisoner at the country house at Thorngrove in Worcestershire until Napoleon's fall in 1814. He then went to Rome, where on 18 August 1814 he was made Prince of Canino by Pope Pius VII and Prince of Musignano on 21 March 1824 by Pope Leo XII.

In 1809 Napoleon increased pressure on Lucien to divorce his wife and return to France, even having their mother write a letter encouraging him to abandon her and return. With the whole of the Papal States annexed to France and the Pope imprisoned, Lucien was a virtual prisoner in his Italian estates, requiring permission of the Military Governor to venture off his property. He attempted to sail to the United States to escape his situation but was captured by the British and spent the years 1810 to 1814 under house arrest in Great Britain. As he got off the ship in England, he was greeted with cheers and applause by the crowd, which saw him as anti - Napoleon. The government permitted him to settle comfortably in the English countryside, where he was working on a heroic poem on the subject of Charlemagne. Napoleon, viewing this as treasonous behaviour, had Lucien omitted from the Imperial almanacs' listing the Bonapartes from 1811 onward. Napoleon was furious thinking Lucien had deliberately gone to Britain. Lucien returned to France following his brother's abdication in April 1814.

In the Hundred Days after Napoleon's return from exile at Elba, Lucien rallied to the imperial cause. His brother made him a French Prince and included his children into the Imperial Family, this was however not recognized by the Bourbons after Waterloo and Napoleon's second abdication. Subsequently Lucien was proscribed at the Restoration and deprived of his fauteuil at the Académie française. In 1836 he wrote his Mémoires. He died in Viterbo, Italy, on 29 June 1840, of stomach cancer, as did his father, his sister Pauline and - according to the official report - Napoleon as well.

Lucien Bonaparte was the inspiration behind the Napoleonic reconstitution of the dispersed Académie française in 1803, where he took a seat. He collected paintings in his maison de campagne at Brienne, was a member of Jeanne Françoise Julie Adélaïde Récamier's salon and wrote a novel, La Tribu indienne.

His first wife was his landlord's daughter, Christine Boyer, the illiterate sister of an innkeeper of Saint - Maximin - la - Sainte - Baume, and by her he had four children, one of whom was stillborn. His second wife was Alexandrine de Bleschamp, widow of Hippolyte Jouberthon, known as "Madame Jouberthon", and by her he had nine children.