He was educated first at Cahors and then studied canon law at Toulouse.
Realizing that he had no calling to the religious life, Joachim left his studies and enlisted in a cavalry regiment. He remained in military service until 1790, at which time he was discharged for disciplinary reasons. Shortly thereafter, he reentered the army (1791).
He was employed by Napoleon Bonaparte on 13 Vendémiaire to aid him in putting down the rising against the Directory. Bonaparte then took him to Italy in 1796 as his first aide-de-camp, where he served during the first Italian campaign. In 1798 he sailed with the Army of Egypt to the banks of the Nile, where he commanded the cavalry during the Battle of the Pyramids. The following year he took part in the Syrian expedition.
In the summer of 1799, when Bonaparte returned to France with only a small group of favored officers, Murat was among them. He was promoted to the rank of general of division in October 1799. On the 18th of Brumaire (Nov. 10, 1799) Murat commanded the grenadiers who evicted the Council of Five Hundred from their meeting hall at Saint-Cloud, thus assuring the overthrow of the Directory and the establishment of the Consulate. Napoleon, the new first consul, appointed him commandant of the consular guard.
The second Italian campaign saw Murat at the head of the cavalry, and he took part in the Battle of Marengo. During the next 4 years of peace on the Continent he was governor of the Cisalpine Republic and governor of Paris. With the creation of the Empire in 1804, he was named marshal. The renewal of hostilities in 1805 found Murat once again at the head of the cavalry. He took an active part in the campaigns of 1806 and 1807 and fought with distinction at Jena, Eylau, and Friedland. In 1808 he was named general in chief of the French Army of Spain. He had high hopes of being named king of Spain, but the Emperor placed his own older brother Joseph on the throne.
As a conciliation, Murat was given the throne of Naples (Aug. 1, 1808). His principal problem was his relationship with his all-powerful brother-in-law. It was Napoleon's intention that the kingdom of Naples should be governed in the best interests of France. Murat balked but remained in line. In 1812 the King of Naples again headed the cavalry of the Grand Army. Throughout the Russian campaign and the retreat, he distinguished himself by his bravery in the face of enemy fire.
When the French retreated beyond the Rhine after the defeat at Leipzig (Oct. 16-18, 1813), Murat retired to Italy. He now realized that the Napoleonic Empire would not survive. He therefore opened negotiations with Austria in an effort to save his throne.
On Jan. 11, 1814, he signed a treaty with Austria that guaranteed him the throne of Naples in return for his renunciation of Napoleon and active military support against France. But Austria was the only great power supporting him, and at the Congress of Vienna the other Allied nations wished to return the deposed King Ferdinand to Naples. Thus, in coordination with Napoleon's return to France in March 1815, but without the returning Emperor's approval, Murat went to war with Austria in the name of Italian unification. The Neapolitan army was defeated in its first engagement with the Austrians, and Murat was forced to flee from his kingdom to France. Napoleon, still furious with his former lieutenant, refused to give him service in the French army or even to allow him to remain on French soil.
In early October he made one last bid to reestablish himself in Italy. Landing at Pizzo on October 8 with a handful of men, he was at once captured. On Oct. 13, 1815, he was condemned to death by a court-martial and shot.
He was noted as a daring, brave, and charismatic cavalry officer as well as a flamboyant dresser.
He married Napoleon's sister, Caroline Bonaparte on Jan. 20, 1800.