Davout was born at
Yonne), the son of Jean-François d'Avout (1739–1779) and his wife (married in 1768) Françoise-Adélaïde Minard de Velars (1741–1810).
:4 He was educated at a
military academy in
Auxerre, before transferring to the
École Militaire in
Paris on 29 September 1785.
 He graduated on 19 February 1788 and was appointed a sous-lieutenant in the Royal-Champagne
:94 On the outbreak of the
French Revolution, he embraced its principles. He was chef de bataillon in a volunteer corps in the campaign of 1792, and distinguished himself at the
Battle of Neerwinden the following spring. He had just been promoted to general of brigade when he was removed from the active list because of his noble birth. He nevertheless served in the campaigns of 1794-1797 on the
Rhine, and accompanied
Desaix in the
Egyptian Expedition of Napoleon Bonaparte.
Although on his return he did not take part in the
Battle of Marengo, where his friend Desaix was killed while making a decisive contribution to the victory.
:65 Napoleon, who had great confidence in his abilities finally promoted him to general de division and arranged his marriage to his sister Pauline's sister-in-law Aimée Leclerc, thus making him part of Napoleon's extended family, and gave him a command in the consular guard. At the accession of Napoleon as emperor, Davout was one of the generals who were created marshals of France. Davout was the youngest and least experienced of the generals promoted to Marshal, which earned him the hostility of other generals throughout his career. As commander of the
III Corps of the
Grande Armée, Davout rendered his greatest services. At the
Battle of Austerlitz, after a forced march of forty-eight hours, the III Corps bore the brunt of the allies' attack. In the subsequent
War of the Fourth Coalition, Davout with a single corps fought and won the
Battle of Auerstädt against the main
 which had more than twice as many soldiers at its disposal (more than 63,000, to Davout's 28,000). Historian François-Guy Hourtoulle writes: "At
Jena, Napoleon won a battle he could not lose. At Auerstädt, Davout won a battle he could not win".
As a reward, Napoleon let Davout and his men enter first in Berlin on 25 October 1806.
Davout added to his renown in the campaign of
Friedland. Napoleon left him as governor-general of the newly created
Duchy of Warsaw following the
Treaty of Tilsit of 1807, and the next year created him
Duke of Auerstädt. In the war of 1809, Davout took part in the actions which culminated in the
Battle of Eckmühl, and also distinguished himself in the
Battle of Wagram, where he commanded the right wing. He was created Prince of
Eckmühl following this campaign. He was entrusted by Napoleon with the task of organizing the "corps of observation of the Elbe", which would become the gigantic army with which Napoleon invaded Russia in 1812. In this, Davout commanded the
I Corps, numbering over 70,000, and defeated the Russians at
Mohilev before he joined the main army, with which he continued throughout the campaign and the retreat from Moscow.
 During the retreat he conducted the rear guard, which was deemed too slow by the Emperor, and was replaced by Ney. His inability to hold out at
Berezina until the arrival of Ney and his corps, led him into disgrace and he would not meet with the Emperor again until his return from Elba.
In 1813 he commanded the
Hamburg military district, and defended Hamburg, a poorly fortified and provisioned city, through a
long siege, only surrendering on the direct order of the new King
Louis XVIII, who had come to the throne after the fall of Napoleon in April 1814.
 During the siege, he expelled up to 25,000 of Hamburg’s poorest and weakest citizens out of the city into the cold winter, many of whom perished of cold and starvation.
 Between 1806 and 1814, when the French occupation came to an end by the surrender of Davout, the population decreased by nearly one-half, namely to 55,000.
Davout's military character has been interpreted as cruel, and he had to defend himself against many attacks upon his conduct at Hamburg. He was a stern disciplinarian, who exacted rigid and precise obedience from his troops, and consequently his corps was more trustworthy and exact in the performance of its duty than any other. For example, Davout forbade his troops from plundering enemy villages, a policy he would enforce by the use of the death penalty. Thus, in the early days of the Grande Armée, the III corps tended to be entrusted with the most difficult work. He was regarded by his contemporaries as one of the ablest of Napoleon's marshals. On the
first restoration he retired into private life, openly displaying his hostility to the
Bourbons, and when Napoleon
Elba, Davout rejoined him.
Appointed Minister of War, he reorganized the French army insofar as time permitted, and he was so indispensable to the war department that Napoleon kept him in Paris during the
Waterloo campaign. To what degree his skill and bravery would have altered the fortunes of the campaign of 1815 can only be surmised, but Napoleon has been criticized for his failure to avail himself in the field of the services of the best general he then possessed.
 However this is countered with the fact that he was the only possible candidate who had not sworn loyalty to the Bourbons and thus had the integrity his role as Minister of War required.
Davout directed the gallant, but hopeless, defence of Paris after Waterloo.
 He received the command of the army assembled under the walls of Paris, and would have fought, had he not received the order of the provisional government to treat with the enemy.
 On 24 June 1815 Davout was sent by
Joseph Fouché, the president of the provisional government, to the dethroned Emperor at
the Élysée Palace with a request to quit Paris, where his continued presence could lead to trouble and public danger. Napoleon received him coldly but left Paris the next day and resided at
Malmaison until 29 June when he departed for Rochfort.
 In later years, Napoleon said of Davout bitterly that ”he betrayed me too. He has a wife and children; he thought that all was lost; he wanted to keep what he had got,”
 while on another occasion he remarked that “I thought that Davout loved me, but he loved only France.”
 Followingly, he retired with the army beyond the
Loire and made his submission to the Bourbon government on July 14, and within a few days gave up the command to
He was deprived of his marshalate and his titles at the second restoration. When some of his subordinate generals were proscribed, he demanded to be held responsible for their acts, as executed under his orders, and he endeavoured to prevent the condemnation of
Michel Ney. After a time the hostility of the Bourbons towards Davout faded, and he became reconciled to the monarchy. In 1817 his rank and titles were restored, and in 1819 he became a member of the
Chamber of Peers.
In 1822, Davout was elected mayor of
Savigny-sur-Orge, a position he held for a year. His son Louis-Napoléon was also mayor of the city from 1843 to 1846. A main square bears their name in the city, as does a boulevard in Paris.
Davout's name, written as Davoust
, appears on the
Arc de Triomphe
, eastern pillar, column 14.