Soult, the eldest son, was destined to take over his father's law practice but preferred to enlist in the Royal Army at age 14. He used his first pay to prevent the family furniture from being seized. After two years of service, he left the military, tried his hand at baking, but re-enlisted rapidly.

In 1789, he adopted Revolutionary ideas and worked his way up the military ladder. In 1794, at age 25, he was noticed at the Battle of Fleurus and named brigadier general. Two years later, he distinguished himself at the Battle of Altenkirchen (June 4, 1796).

In September 1799, now division general of the Army of Helvetia, he took part in the victory at Zurich under Masséna's orders. He followed his commander to the Army of Italy and participated in the defense of Genoa, while Bonaparte was crossing the Great Saint Bernard Pass.

In late 1800, the First Consul sent him to pacify Piedmont. In 1802, Soult became colonel-general of the Consular Guard light infantry and a fervent Bonapartist. The advent of the Empire (1804) brought him titles and glory. He was named marshal on May 19 and grand-officer of the Légion d'Honneur.

As commander of the Saint-Omer camp in Boulogne, Soult trained the 4th corps of the Grande Armée, imposing strict discipline on his men. His reputation of being a merciless leader began here, and he was nicknamed "Iron" by his soldiers.

His army corps played an essential role at the Battle of Austerlitz (December 2, 1805), seizing the Pratzen Plain. Napoleon complimented him on his action, calling him "the finest tactician in Europe." Soult then participated in the Prussian and Polish campaigns, namely distinguishing himself at Jena (October 14, 1806) and at Eylau (February 8, 1807). On June 16, 1807, he captured the town of Königsberg.

In 1808, he accompanied Napoleon to Spain. Created Duc de Dalmatie, he commanded the 2nd corps of the Grande Armée. First victorious, he advanced to Portugal. He imposed order there and let it be rumored that he could be the next King of Portugal. Wellington dashed his hopes when he defeated him at Oporto. The French marshal got his revenge at Ocaña on November 19, 1809.

Major general under Joseph, restored to the Spanish throne, Soult managed to subdue Andalusia in 1810 and became governor of the province. In 1812, he was forced to retreat by Wellington's victorious troops.

In 1813, after a short stay in Germany, he was again sent to Spain to fight Wellington. He was unable to halt the English general, whose forces outnumbered his four to one, and had to cross the Pyrenees. Beaten at Orthez on February 27, 1814, he resisted fiercely, slowing down Wellington's advance by every means. In April, he maintained a siege at Toulouse 25,00 men against 100,000 enemy forces until the news of the Emperor's abdication.

Under Louis XVIII, Soult became War Minister. Napoleon, back from Elba, forgave him for his anti-Bonapartist declarations Soult had called him a "usurper" and an "adventurer" and named him major general of his army. Though he was not as efficient as Berthier, he nonetheless fought courageously at Waterloo, on June 15-18, 1815.

After the defeat, Soult retired to his Soulberg château, amidst his fine collection of paintings by Spanish masters, the result of his looting. His protests had not made the king bend. He was pardoned in 1819 and had his titles restored the following year.

Peer of France under Charles X, he played his most important political role under Louis Philippe, as War Minister and then president of the Council. In April 1838, he was France's ambassador to the coronation of Queen Victoria in England. This was the prelude to a career as Minister of Foreign Affairs, quickly interrupted by the arrival in power of Thiers, his rival.

In 1847, the old marshal retired permanently, with the glorious title of Marshal general.