- 2 May
- 1808 : Anti-French uprising of the people of Madrid.
- 1813 : Battle of Lützen.
- 3 May
- 1804 : Adoption by the Tribunes, with one vote against, of the motion to raise Napoleon Bonaparte dignity to the one of Emperor of the French.
- 1811 : Massena's victory over Wellington at Fuentes de Oñoro.
- 1814 : Arrival of Napoleon at Elba. Entry of Louis XVIII in Paris.
- 4 May
- 1802 : Filing of a bill establishing the Legion of Honor.
- 1807 : Signing of a pact of friendship between France and Persia, at Finckenstein.
- 1810 : Birth of Alexandre Walewski, the illegitimate son of Napoleon and Maria Walewska.
- 1814 : Landing of Napoleon to Elba.
- 5 May
- 1808 : Interview of Bayonne. The Spanish crown is placed at the disposal of Napoleon.
- 1812 : The Emperor leaves Paris. He shall not see it again until March 21, 1815.
- 1821 : Death of Napoleon.
- 6 May
- 1805 : Reconciliation of Napoleon and his brother Jerome, who agrees to divorce.
- 7 May
- 1796 : Entry of Bonaparte at Piacenza.
- 8 May
- 1801 : In Saint-Domingue, Toussaint Louverture enacts a constitution.
- 1802 : Extension of ten years of the mandate of the First Consul. A Senator proposes that Bonaparte gets this dignity for the rest of his life.
- 1805 : Villeneuve and his fleet arrive in Martinique but fail to operate their junction with that of Rochefort, commanded by Missiessy.
- 9 May
- 1796 : Signing of a truce with the Duke of Parma.
- 10 May
- 1796 : Victory of Lodi. Bonaparte is promoted to corporal by his soldiers.
- 1806 : University Foundation.
- 1811 : Massena is replaced by Marmont at the head of the army of Portugal.
- 11 May
- 1803 : France rejects the British ultimatum demanding the evacuation of Holland and approval of the British presence in Malta.
- 1809 : Installation of Napoleon at Schoenbrunn Palace.
- 12 May
- 1802 : The consulate for life is passed unanimously minus the voice of Carnot in Tribunate, unanimously minus three votes in the Body legislature.
- 1803 : Out of the Treaty of Amiens.
- 1814 : Twelve thousand officers, declared supporters of Napoleon, are set half-pay.
- 13 May
- 1801 : Cutting of the Cisalpine Republic in twelve departments.
- 1809 : Signature of the capitulation of Vienna.
- 1814 : Ferdinand VII comes back in Madrid. He instantly reinstalls the Inquisition and absolute monarchy.
- 14 May
- 1802 : Amnesty for the crimes of desertion committed in France by soldiers of the French troops.
- 15 May
- 1779 : Admission of Bonaparte at the military school of Brienne.
- 1796 : Entry of Bonaparte in Milan.
- 1797 : Occupation of Venice. Leak of the Doge.
- 1815 : Royalist rebellion in the Vendee.
- 16 May
- 1797 : Signing of a peace treaty with Venice.
- 1806 : The British government decides to blockade the coast and ports, from the Elbe to Brest.
- 1811 : Soult is defeated at the Albuera by an army Anglo-Hispano-Portuguese.
- 17 May
- 1799 : Lifting of the siege of Saint Jean d'Acre.
- 1809 : Meeting of the Papal States to the French Empire.
- 18 May
- 1802 : The purchase of a replacement by the conscript becomes legal.
- 1804 : A Senatus-consultum who proclaims Napoleon Bonaparte Emperor of the French is approved unanimously least three votes.
- 19 May
- 1798 : Departure for Egypt.
- 1802 : Adoption of the bill establishing the Legion of Honor.
- 1804 : Appointment of fourteen marshals of the Empire: Berthier, Murat, Moncey Jourdan, Massena, Augereau, Bernadotte, Soult, Brune, Lannes, Mortier, Ney, Davoust, Bessieres, and of four marshals-Senators: Kellermann, Lefebvre, Perignon, Serrurier.
- 20 May
- 1800 : Passage of the col of Saint-Bernard.
- 1802 : The law of 30 Floréal Year X (20 May 1802) established that in the colonies returned to France in execution of the Treaty of Amiens [...],
slavery was maintained in accordance with the laws and regulations prior to 1789 (article 1). The same shall apply in the other French colonies beyond the Cape of Good Hope (article 2).
- 21 May
- 1809 : First day of the Battle of Essling.
- 1813 : Battle of Bautzen.
- 22 May
- 1809 : Second day of the Battle of Essling. Fatal injury of Marshal Lannes.
- 1813 : Death of Duroc.
- 23 May
- 1803 : Declaration of war against England.
- 1808 : Beginning of the Spanish insurrection.
- 24 May
- 1806 : Removing of the republican regime in Holland.
- 1808 : The Duchies of Parma, Piacenza and Tuscany are united to Empire.
- 25 May
- 1804 : Starting of the trial of Cadoudal, Moreau and their forty-five co-defendants.
- 26 May
- 1796 : Taken of Pavia.
- 1805 : Coronation of Napoleon as King of Italy in the Cathedral of Milan.
- 1807 : The Marshal Lefebvre gets the capitulation of Danzig.
- 27 May
- 1796 : Entry in Brescia.
- 1799 : Second visit to the plague victims of Jaffa.
- 1803 : Invasion of Hanover by Mortier.
- 1808 : Anti-French protests in Valencia. Four hundred French are killed.
- 1814 : Davout evacuates Hamburg.
- 28 May
- 1808 : Uprising of the people of Cadiz.
- 29 May
- 1802 : Adoption of the act of Malmaison by an assembly of notables Swiss.
- 1814 : Death of Josephine at Malmaison.
- 30 May
- 1806 : An assembly of one hundred-eleven chiefs of the nation Jewish is convened in Paris.
- 1808 : Insurrection and massacre at Granada.
- 31 May
- 1808 : Uprising of Valladolid.
- 1814 : Arrival of Pauline Bonaparte to Elba.