- 1st April
- 1802 : A new voting rule divides the Tribunate into three sections. They deliberate separately.
- 1810 : Celebration of the civil marriage of Napoleon and Marie-Louise of Austria in Saint-Cloud.
- 1814 : Appointment of a provisional government by the Senate.
- 2 April
- 1801 : Nelson and his fleet bombard Copenhagen.
- 1810 : Celebration of the religious marriage of Napoleon and Marie-Louise of Austria in the Salon Carre of the Louvre.
- 1814 : Proclamation by the Senate of the downfall of Napoleon and his family.
- 3 April
- 1814 : The legislative body vote the revocation of Napoleon.
- 4 April
- 1814 : First abdication of Napoleon.
- 5 April
- 1814 : Napoleon reviews debris of his guard.
- 6 April
- 1804 : Suicide of Pichegru.
- 1814 : Council of Napoleon's marshals. "Louis-Stanislas-Xavier" (Louis XVIII) is called to throne by the Senate.
- 7 April
- 1802 : Adoption of the Concordat by the Tribunes.
- 8 April
- 1802 : Adoption of the Concordat by the legislative body.
- 1809 : The Austrian army crosses the Inn near Braun and enters into Bavaria.
- 9 April
- 1809 : Declaration of war from Austria to France.
- 1815 : Victory of the Austrians on Murat at Ochiobello.
- 10 April
- 1805 : Arrival of Admiral Villeneuve and his fleet in Cadiz.
- 1809 : Entry of the Archduke John in Italy at the head of an army Austrian.
- 1814 : Wellington's Victory on Soult at Toulouse.
- 11 April
- 1803 : Creation of the schools of pharmacy.
- 1805 : England and Russia sign the Convention of Saint-Petersburg, which seals their alliance.
- 1811 : The Spanish guerrillas attack the French army at the Avis Pass (Fight of Guisando).
- 12 April
- 1796 : Battle of Montenotte.
- 1803 : Regulation of the operation of the factories and workshops. Prohibition of the coalitions of workers. Establishment of Protection trademarks.
- 1814 : Napoleon attempts to commit suicide.
- 13 April
- 1796 : Battle of Millesimo.
- 1804 : The Privy Council chooses the title of Emperor for Napoleon.
- 14 April
- 1802 : Publication of Chateaubriand's Genius of Christianity, dedicated to the First Consul.
- 1803 : The Bank of France obtains for fifteen years the exclusive privilege of issuance of banknotes.
- 1815 : Benjamin Constant is requested to draft a constitution.
- 15 April
- 1796 : Victory of Dego.
- 1808 : Louis Bonaparte refuses the crown of Spain. Napoleon offers it to Jerome, who also refuses.
- 1811 : Abolition of feudalism in Illyria.
- 16 April
- 1799 : Battle of Mount Tabor.
- 17 April
- 1797 : Massacre of the French in the region of Verona.
- 18 April
- 1797 : Signature of the preliminaries of the peace of Leoben.
- 19 April
- 1809 : Davout defeats Archduke Charles at Tengen.
- 20 April
- 1808 : Birth of Louis-Napoleon Bonaparte, future Napoleon III.
- 1814 : Farewell of the Emperor to his close relations.
- 21 April
- 1795 : Engagement of Napoleon and Desiree Clary.
- 1796 : Battle of Mondovi.
- 22 April
- 1806 : Admiral Villeneuve commits suicide. Napoleon wanted to put him in accusation.
- 1809 : Battle of Eckmühl.
- 1815 : Publication of the Supplementary Act to the Constitutions of the Empire.
- 23 April
- 1804 : Proposal to raise Napoleon Bonaparte's dignity to the one of hereditary Emperor of the French.
- 1809 : Taken of Regensburg. Slight wound of the Emperor.
- 24 April
- 1812 : Publication of a Russian ultimatum.
- 25 April
- 1814 : Hostility to the passage of Napoleon in Provence.
- 26 April
- 1802 : Conditional amnesty to all exiles.
- 27 April
- 1807 : The Emperor receives the Persian ambassador, Mirza Reza, at Finckenstein.
- 28 April
- 1796 : Signing of the Armistice of Cherasco with the kingdom of Sardinia.
- 29 April
- 1801 : The First Consul, acting as arbiter of the conflict between centralist and federalist in Switzerland Republic, offers them the act of Malmaison. Nobody is satisfied.
- 1814 : In Hamburg, Davoust agrees to recognize the authority of Louis XVIII but continues to defend the city.
- 30 April
- 1803 : The United States purchase the Louisiana.
