- 1st September
- 1814 : Arrival of Maria Walewska and his son to the island of Elba.
- 3 September
- 1806 : Pierre Oubril notifies the France of the Czar's refusal to ratify the draft Treaty signed last July 20.
- 4 September
- 1796 : Victory of Roveredo.
- 1797 : Directorial coup of 18 Fructidor.
- 1809 : The English fail in Antwerp.
- 5 September
- 1800 : Fall of Malta to the English.
- 6 September
- 1798 : Seid Mohammed el-Koraim is executed on the orders of General Bonaparte, for having betrayed the Republic.
- 1801 : Creation of the body of inspectors general of the Treasury public.
- 1813 : Ney is defeated at Dennewitz.
- 7 September
- 1804 : Napoleon gathers at the tomb of Charlemagne, in Aix-la-Chapelle.
- 1812 : Battle of Borodino.
- 9 September
- 1805 : Restoration of the Gregorian calendar by Senatus-consultum.
- 1813 : Töplitz Treaty between Russia, Prussia and Austria.
- 10 September
- 1805 : Invasion of Bavaria by the Austrian army. Naples signs a treaty of neutrality with France.
- 1808 : Married men and widowers fathers are exempted from military service.
- 11 September
- 1802 : Meeting of the Piedmont to France.
- 1805 : Naples signes a secret treaty of alliance with Russia and England.
- 1807 : Publication of the "Commercial Code".
- 12 September
- 1806 : The Prussian army enters in Saxony.
- 13 September
- 1802 : In Saint-Domingue, uprising of black slaves.
- 1806 : Death of Charles James Fox, the only strong supporter of peace in British government.
- 14 September
- 1807 : Capitulation of the British expeditionary force in Egypt, facing Mehemet Ali.
- 1812 : Napoleon enters Moscow. City fire by Russians.
- 15 September
- 1796 : Battle of Saint-Georges.
- 1802 : Joseph Fouche leaves the department of Police General.
- 16 September
- 1796 : Second day of the Battle of Saint-Georges.
- 1807 : Creating the Court of Auditors.
- 17 September
- 1796 : Establishment of the Cispadan Republic.
- 1807 : Napoleon sends Villeneuve an order to leave Cadiz for support operations of Saint-Cyr in Italy.
- 1808 : Granting a monopoly on teaching at the University.
- 18 September
- 1801 : Opening of the exhibition of national industry in the courtyard of the Louvre.
- 1812 : Wellington besieges Burgos.
- 19 September
- 1796 : Carnot congratulates Bonaparte for his victory of Bassano.
- 1811 : Napoleon's departure for Holland.
- 20 September
- 1796 : Talleyrand returns from America.
- 21 September
- 1805 : Commitment to neutrality of the King of Naples in case of war between France and Austria.
- 22 September
- 1802 : Visit of the exhibition of national industry in the Louvre and of the Salon of painting and sculpture.
- 23 September
- 1800 : Bonaparte lays foundation stone of the monument to Kleber and Desaix, Place des Victoires.
- 1805 : Announcement to the Senate of the rupture with Austria.
- 24 September
- 1803 : Last edition of the feast of the founding of the Republic.
- 1812 : Napoleon confidentially offers peace to the Tsar.
- 25 September
- 1796 : Creating of the company of guides, nucleus of the future Imperial guard.
- 1805 : Passage of the Rhine by French troops.
- 26 September
- 1805 : Financial panic in Paris.
- 27 September
- 1800 : Establishment of a Treasury Department.
- 1808 : Meeting of Napoleon and of the Czar in Erfurt.
- 28 September
- 1805 : Nelson takes command of the English fleet which blocks Cadiz.
- 1808 : In Erfurt, Talleyrand warns the Tsar against the "madness" of Napoleon.
- 29 September
- 1801 : Signing of a peace treaty between the French Republic and the kingdom of Portugal.
- 30 September
- 1800 : Signature of the Franco-American treaty of Mortefontaine, which terminates a quasi war between the two countries.
- 1802 : The First Consul imposes his mediation to Swiss cantons in the conflict between the Federalists and the Unitarians.
- 1806 : Creation of the reserve army of the Rhine. Marmont defeats a Russian army in Castelnuovo.
- 1813 : A raid of the Cossack forces King Jerome Bonaparte to flee Cassel, his capital.