| 1839 | | Captain Louis Bouet Willaumez signs a convention with King Denis Rapontchombo chief of the Mpongwé granting the French residence rights on the left bank of the Gabon. |
| 1842 | | Captain Louis Bouet Willaumez signs accords with Gabonese chiefs Louis Dowe, Glass, Quaben and Georges securing better positions for France on the right bank of the Gabon. The primary object of the French settlement was to secure a port where warships could be re-supplied. |
| 1843 | September 29 | Father Jean René Bessieux the only survivor among the six missionaries sent to the Guinea Coast by the Holy Ghost Fathers succeeds in reaching the French Navy post at Cape Palm at the mouth of the Gabon and establishes a mission station on the spot. |
| 1845 | | Gabon becomes part of the newly formed colony of Les Rivieres du Sud which includes all French settlements in Africa south of Senegal under the administrative rule of the admiral in command of the Goree Island Naval Station. |
| 1849 | | The French Navy captures a slave ship and releases the forty-nine slaves who are settled near Father Bessieux’s mission station on a little plateau which is henceforth called Libreville. Father Bessieux is recalled to Europe, consecrated bishop, and sent back to Gabon as Vicar Apostolic of the Two Guineas and Senegambia. |
| 1856 | December | American Paul du Chaillu returns to Gabon where he had spent several years of his youth with his father who operated a trading post a few miles north of the equator. Du Chaillu spends the next 3 ½ years exploring the territory stretching from the mouth of the Gabon 320 miles inland and 250 miles north and south. |
| 1861 | | Paul du Chaillu’s book Explorations and Adventures in Equatorial Africa with Accounts of the Manners and Customs of the People, and of the Chase of the Gorilla, Crocodile, Leopard, Elephant, Hippopotamus, and other Animals is published in America by Harper Brothers. Du Chaillu’s fanciful depictions including the first reported sighting of a live gorilla are greet with popular derision but are subsequently proved true. |
| 1862 | | Cape Lopez is ceded to France under a treaty signed by the local chiefs. |
| 1863 | | Paul du Chaillu begins a two year exploration of interior Gabon south of the Ogowe River. |
| 1864 | | Griffon du Bellay, a French Navy doctor, returns to Europe with the first samples of Ibogaine, a substance later used in the treatment of heart disease and cancer before being outlawed owing to its psychotropic properties. |
| 1867 | | Libreville’s garrison numbers about 1,000. The civilian population numbers about 5,000. Official reports claim the entire 8,000 square mile colony has a population of 186,000. |
| | Paul du Chaillu’s account of his second expedition to Gabon, A Journey through Ashango Land, is published. Du Chaillu’s claims, in particular his reported encounter with the Pygmies, are again the source of popular distain. |
| 1871 | | The Franco-Prussian War results in the near abandonment of the Gabon colony. Libreville is reduced to the status of a coaling depot for French warships. |
| 1873 | February 15 | French naturalist Alfred Marche and the Marquis de Compiegne arrive in Gabon where they explore a portion of the Ogowe Basin. |
| During the Year | King Nyanguényona of the Orungu cedes the Isle of Mandji to the French. |
| | 1875 – 1878 Pierre Savorgnan de Brazza, accompanied by Doctor Noel Eugene Ballay and, for part of the time, by Alfred Marche, explores the country east of the Ogowe River. De Brazza’s expedition ascends the Ogowe for over 400 miles and beyond the basin of that stream discovered the Alima, a tributary of the Congo. |
| 1878 | November | De Brazza and Ballay turn north from the Alima and finally reach the Gabon. |
| 1879 | December 27 | Pierre Savorgnan de Brazza sets out to find a route to the upper Congo via the Ogowe. |
| 1880 | June | Pierre Savorgnan de Brazza founds the town of Franceville at the confluence of the Passa and the Ogowe. |
| December | Pierre Savorgnan de Brazza returns to Libreville having descended the Congo where he had met with Henry Morton Stanley. |
| During the Year | The French settlement of the Isle of Mandji begins with the establishment of the Cape Lopez trading post. |
| 1881 | | Pierre Savorgnan de Brazza establishes the post of Alima then descends the Niari River, the shortest route to the Middle Congo, and returns to the coast. |
| | The administration of Gabon is entrusted to a senior naval officer with the title of High Commander of the French Settlements on the Gulf of Guinea. |
| | The Catholic mission of Saint Francis Xavier is established at Lambarene on the Ogowe. |
| 1883 | | Pierre Savagnon de Brazza is appointed Commissioner of the French Republic in West Africa. The French settlements in West Africa are divided into two entities: Gabon administered by its own commandant and having Cotonou and Porto Novo as dependencies, and Grand Bassam and Assinie on the Ivory Coast. |
| 1885 | December 24 | A Franco–German protocol establishes a boundary between their respective territories inland from the Bight of Biafra along the Campo River to the 10th meridian, and thence from the point of intersection, the parallel of latitude 1 to the 15th meridian. |
| 1886 | June 29 | Pierre Savagnon de Brazza is appointed Commissioner General of Government with authority over the colonies of French Congo and Gabon, each with their separate government organization. Noel Ballay is appointed Lieutenant Governor of Gabon. |
| During the Year | The French post at Cape Lopez includes 18 warehouses, a customs house and two stores. |
| 1888 | December 11 | The French Congo and Gabon are combined as a single administrative entity. |
| 1891 | April 30 | The title of French Congo is applied to the unified administrative entity composed of the old French Congo and Gabon. |
| 1900 | | The Gabon-Spanish Guinea border is delimited in a Franco-Spanish convention. |
| 1903 | December 29 | The French colonies of Gabon and Middle Congo, the territory of Ubangi–Shari, and the military territory of Chad are placed under the authority of a Commissioner General. |
| 1908 | April 18 | A Franco–German convention again delimits the boundary between Cameroon and the French territories from Spanish Guinea to Lake Chad. |
| November 4 | Another Franco–German convention places the boundary between Gabon and Cameroon a considerable distance south of the present line. |
| 1910 | January 15 | The colonies of Gabon, Middle Congo, and Ubangi–Shari–Chad are incorporated into French Equatorial Africa but each retains its own lieutenant governor. |
| 1911 | November 4 | A large strip of territory in northern Gabon is ceded to the German colony of Cameroon. |
| 1913 | | Albert Schweitzer completes his medical studies at the University of Strasbourg and builds a dispensary at Lambaréné. |
| 1917 | | Albert Schweitzer and his wife are interned by the French as enemy aliens until the end of the war. |
| 1919 | | French territory ceded to the German colony of Cameroon under a 1911 convention is restored to Gabon. |
| 1922 | | Léon M’Ba, a Fang and future President of Gabon, is appointed chief of his town. |
| 1924 | | Albert Schweitzer returns to Lambaréné where spends most of the remainder of his life. |
| 1925 | | The Upper Ogowe basin is transferred to the jurisdiction of the Middle Congo to facilitate construction of the Congo-Ocean Railway. |
| 1933 | | Léon M’Ba is exiled to Ubangi-Shari for protesting the French administration’s abuse of conscript native labor. |
| 1940 | August 29 | Governor Georges Masson receives a telegram from General de Larminat informing him of the Free French takeover in Brazzaville . Masson informs the commandant of the local garrison and publicly declares Gabon’s adhesion to Free France. The naval commander of Libreville opposes the move and informs the governor that a Vichy naval squadron is about to arrive from Dakar. Masson yields and labels the affair a misunderstanding. Several prominent Gaullists in the colonial establishment are deported to Dakar by flying boat. Vichy dispatches Air Force General Tetu to Libreville as Governor General of French Equatorial Africa with orders to reestablish its control throughout the colonies. |
| September 17 | A Vichy naval task force departs Dakar, Senegal for Libreville with orders to reestablish Vichy’s authority in Gabon. |
| September 18 | The Vichy naval task force is intercepted by the Royal Navy and ordered to turn for Casablanca. Two cruisers comply with the order but the remaining Vichy ships return to Dakar. |
| October 8 | The Vichy submarine Poncelet is sunk off the coast of Gabon by HMS Milford. |
| October 9 | The Free French patrol sloop Savorgnan de Brazza sinks the Vichy cruiser Bougainville off Gabon. |
| October 12 | General de Gaulle issues orders for liquidation of the Vichy enclave in Gabon. |
| October 27 | Free French troops from Cameroon capture the Vichy post at Mitzic. |
| November 5 | The Vichy garrison at Lambarene surrenders. |
| | Free French troops under Generals Le Clerc and Koenig depart Douala, Cameroon bound for Libreville. |
| November 8 | General Koenig’s mixed force of Legionnaires, Senegalese and Cameroonian troops make a late night landing at Pointe La Mondah. |
| November 9 | Battle of Libreville - Koenig encounters heavy resistance from Vichyites during the march on the colony’s capital. Free French Lysanders from Douala bomb the aerodrome. A Free French naval force under the command of Captain Thierry d’Argenlieu opens fire on the Vichy cruiser Bougainville setting her ablaze. Koenig’s legionaires break Vichy resistance at the aerodrome. D’Argenlieu accepts General Tetu’s surrender. |
| November 12 | Free French take Port Gentil, the last Vichy stronghold in Gabon. The sole casualty is former Governor Masson who goes along with the expedition hoping to persuade the garrison to surrender peacefully. Masson having declared for de Gaulle then reneged only to be replaced by Vichy. Despair of facing the consequences leads the former governor to commits suicide. |
| November 15 | General de Gaulle visits Vichy prisoners in Gabon and attempts to win them over to Free France. Most reject the offer and are interned along with General Tetu at Brazzaville. |
| During the Year | Spanish nationalists propose annexation of Gabon claiming the territory is within borders allocated to Spain by the 1778 treaty of El Pardo. The proposal is not taken up by the Spanish government. |
| 1946 | | The Upper Ogowe region transferred to the Middle Congo to facilitate construction of the Congo-Ocean Railway is restored to Gabon. |
| | Gabon is made a French Overseas Territory under the Constitution of the Fourth Republic. Jean-Hilaire Aubame is elected to represent Gabon in the Chamber of Deputies. Léon M'Ba is elected Mayor of Libreville and founds the Gabonese Democratic Block (BDG). |
| 1953 | December 10 | Albert Schweitzer accepts the 1952 Nobel Peace Prize. The $33,000 prize money is used to start a leprosarium at Lambaréné. |
| 1958 | | Gabon becomes an autonomous republic within the French Community following a 92% vote in favor of the Constitution of the Fifth Republic. |
| 1960 | July 12 | Transfer of power and cooperation agreements between the French and Gabonese governments are signed in Paris. |
| August 17 | The Gabon Republic is declared independent. |
