| 1908 | November 15 | Belgium assumes sovereign rights over the Congo. Administrative control is transferred to the Ministry of Colonies. |
| 1909 | January | Germany becomes the first nation to accord diplomatic recognition to Belgium's assumption of sovereignty over the Congo. |
| | Sir Arthur Conan Doyle pens The Crime of the Congo, a book detailing the atrocities committed against the natives of the Congo during the regime of King Leopold II. |
| 1911 | | Katanga is linked to South Africa by rail via Rhodesia. |
| 1912 | May 20 | Félix Fuchs succeeds Baron Wahis as Governor General of the Belgian Congo. |
| 1913 | | Diamonds are discovered in Kasai Province. |
| 1914 | August 22 | The German gunboat von Wissman shells Albertville on Lake Tanganyika. |
| August 23 | The German Foreign Office proposes neutralization of European colonies in the Congo basin. The Allies reject the proposal. |
| August | German forces capture Ngoma on Lake Kivu and hold the station for the next 9 months. |
| | The Belgian gunboat Alexandre Delcommune is disabled on Lake Tanganyika. |
| 1915 | February | Belgian shore batteries on Lake Tanganyika put the German gunboat von Wissman out of commission for 10 weeks. |
| March | Albertville on Lake Tanganyika is linked by rail with the navigable portion of the Upper Congo. The Congo's railways and navigable rivers now link the Atlantic with Lake Tanganyika. |
| July - August | Belgian Congo and British troops hold off German attacks on Saisi, Northern Rhodesia. |
| August 29 | Belgian forces hold off a 14 hour attack on Luvungi killing 68 German troops. |
| December 26 | Two British gunboats, Mimi and Tou-Tou, hauled overland from the Atlantic to Lake Tanganyika sink the German gunboat Kingani after a 10 minute fight. The Kingani is refloated and renamed Fife. |
| During the Year | A uranium bearing pitchblende deposit is discovered at Shinkolobwe in Katanga. The discovery is kept secret until after the war by Union MInière du Haut Katanga. |
| 1916 | January 5 | Eugène Henry succeeds Félix Fuchs as Governor General of the Belgian Congo. |
| February 9 | The Belgian gunboat Alexandre Delcommune and the British gunboats Mimi and Fife sink the German gunboat von Wissman on Lake Tanganyika. |
| July 28 | The German steamer Graf von Gotzen is destroyed while attempting to land troops on Belgian Congo shore of Lake Tanganyika by the Belgian gunboat Netta. |
| July 29 | Belgian troops capture the German East African towns of Ujiji and Kigoma on Lake Tanganyika. Rolling stock is ferried across the lake from Albertville in the Belgian Congo and a systematic advance along the rail line to Tabora begins. |
| September 11 | Tabora falls to Belgian and British troops against considerable resistance. |
| 1917 | | Cotton cultivation is introduced in the Maniema region. |
| | Diamond mines are opened in Kasai Province. |
| 1919 | April 21 | The number of Spanish influenza victims in the Belgian Congo reaches 500,000. |
| May 4 | Workers strike mines and railways in the Belgian Congo’s Katanga province. |
| 1920 | July 1 | Regular air transport service is inaugurated in the Congo. La Ligne Aérienne Roi Albert (King Albert Airlines) begins service on the Léopoldville-N'Gombé route, covered by Lévy-Lepen seaplanes following the Congo. The route is later extended as far as Stanleyville. |
| During the Year | L'Avenir Colonial Belge, the first daily newspaper in the Belgian Congo, begins publication. |
| 1921 | January 30 | Maurice Lippens succeeds Eugène Henry as Governor General of the Belgian Congo. |
| June | Simon Kimbangu founder of Protestant sect preaching belief in faith healing and strict adherence to Mosaic Law is imprisoned by authorities who believe the movement is getting out of control. The Church is banned and its members exiled to remote rural regions. Kimbangu escapes detention in a matter of days. |
| September | Simom KImbangu surrenders to the Government and is sentenced to death for hostility to the State. The sentence is commuted to life in prison. |
| December 2 | The capital of the Belgian Congo is moved from Boma to Kinshasa. Kinshasa is renamed Leopoldville. |
| December | Société Générale Métallurgique de Hoboken refines the first radium produced from Congolese pitchblende at a factory at Olen, near Antwerp. |
| 1923 | January 24 | Martin Rutten succeeds Maurice Lippens as Governor General of the Belgian Congo. |
| 1924 | | Union Minière du Haut Katanga discovers pitchblende deposits containing high concentrations of radium and uranium in the Belgian Congo. Belgium monopolizes the world market and the price of radium rises to $70,000 per gram. |
| 1925 | August 21 | Ruanda and Urundi are united with the Belgian Congo for administrative purposes. |
| During the Year | Sabena pilot Edmond Theiffry completes the first airplane flight between Brussels and Leopoldville in the Congo in a Handley Page W8f. The 8,125 km route is covered in 51days (75 hours, 25 minutes flying time). |
| 1926 | | SABENA completes airfields in the Congo and begins flights between Boma, Leopoldville and Elisabethville, a 1422 mile route over dense jungle. Planes are shipped from Antwerp and reassembled in the Congo. |
| | The Standard Chemical Company of Pittsburgh abandons the radium refining business giving Union MInière du Haut Katanga a near monopoly. Radium is marketed at $70,000/gram. |
| 1927 | December 27 | Auguste Tilkens succeeds Martin Rutten as Governor General of the Belgian Congo. |
| 1930 | March 25 | Socialist leader Emil Vandervelde denounces the treatment of Congolese laborers in an address to the Chamber of Deputies. |
| 1931 | March 1 | Extension of the Benguela Railway from Luao to Tenke in the Belgian Congo is completed. The 335 mile extension closes the final link in the first trans-African railway joining Lobito Bay on the Atlantic with Beira, Mozambique on the Indian Ocean. |
| May 11 | The Association of Belgian Colonists in Katanga sends a memorandum to the Colonial Secretary asking for greater autonomy and urging creation of a provincial parliament for Katanga to be elected by vote of Belgian colonists. |
| May 14 | General Pilkens, Govenor General of the Congo, is recalled for consultation on emergency measures to relieve the serious economic crisis in the colony. |
| 1934 | September 14 | Pierre Ryckmans succeeds Auguste Tilkens as Governor General of the Belgian Congo. |
| 1935 | February 23 | SABENA begins regularly scheduled service between Brussels and Leopoldville in the Congo. Prosper Cocquyt pilots a Fokker F7b on the first flight which takes 5 ½ days (56 hours flying time). |
| 1936 | April 23 | Shareholders of the Compagnie du Chemin de Fer du Congo (Congo Railways) approve a takeover of the railway’s assets by the government. |
| 1937 | | Union MInière du Haut Katanga closes its mine at Shinkolobwe. The more than 2,000 tons of ore containing 65 per cent U3O8 which are stockpiled, is believed sufficient to supply the world's radium demand for about 20 years. |
| 1938 | August 8 | The last section of the Congo automobile road, a portion of the Cape to Cairo route, is completed. |
| November 3 | Premier Spaak rejects suggestions that Belgium join in appeasing Germany by ceding all or part of the Congo in a speech to the Chamber of Deputies. |
| During the Year | Union Minière du Haut Katanga and Eldorado Gold Mines of Canada form radium cartel which gives the Belgians 60% of the world market. The price of radium rises to $25,000/gram after earlier competition threatened to send it below $10,000. |
| 1939 | August 2 | Albert Einstein writes a letter to President Roosevelt discussing the possible development of atomic weapons and suggesting the Belgian Congo as a source of uranium. |
| August 15 | Leo Szilard sends a memorandum to President Roosevelt suggesting that a stockpile of uranium ore be obtained from Belgium or the Belgian Congo for use in the development of atomic weapons. |
| September 3 | The 1st Battalion of the Northern Rhodesia Regiment is sent to guard the Belgian Congo border from an imagined invasion by a mythical 1300 man mechanized force supposedly raised in Portuguese Angola. |
| September | Sabena moves the European terminus of its Congo air route from Brussels to Marseilles. |
| 1940 | May 28 | The Government informs the Governor General of the Congo, Pierre Ryckmans, that Belgium is still at war and he is to ignore the King’s actions. |
| May 31 | The Government of the Belgian Congo orders all gold produced in the colony to be sold to it for delivery to the South Africa Reserve Bank at Pretoria. |
| July 22 | Governor General Ryckmans, speaking on a broadcast from Elisabethville, declares that the Belgian Congo is prepared to stand by Great Britain until victory is achieved and Belgium liberated. |
| August 16 | Free French representative, Colonel de Larminat, arrives in Leopoldville to co-ordinate the rally of the French Congo with Captain Delange and Surgeon General Sicé, leaders of the Gaullists in Brazzaville. Governor General Ryckmans of the Belgian Congo supports the Free French. |
| August 27 | The Free French representative in Leopoldville, Colonel de Larminat, delivers an ultimatum demanding the rally of French Congo to Governor General Husson in Brazzaville. |
| September | Governor General Ryckmans announces the arrival in Leopoldville of a British military and economic mission to help mobilize the Congo’s defenses. |
| October 27 | General de Gaulle takes time out from his tour of French Equatorial Africa to visit Leopoldville as guest of honor at a reception hosted by Governor General Ryckmans. Ryckmans expresses his gratitude to the Free French for protecting his colony from infection by the spirit of capitulation. |
| During the Year | The Belgian Congo's stockpile of uranium bearing ore is shipped to the United States. |
| 1941 | January 21 | An Anglo-Belgian accord transfers Belgian Congo gold production and foreign exchange to the Bank of England in return for payment in sterling. The value of the Belgian Congo franc is pegged at 176 = £1 sterling. |
| November 10 | Katanga miners stage a two day strike. |
| December 4 - 10 | A general strike in Katanga in protest of inflated living costs is suppressed by troops who kill 70 strikers. |
| December 6 | Pan American Airways’ Capetown Clipper begins its first flight from New York to Leopoldville in the Belgian Congo. |
| During the Year | 30,000 native Congolese troops under the command of Belgian officers assist the successful British campaign in Ethopia. |
| 1942 | January 29 | Air service between Leopoldville and Capetown via Elizabethville inaugurated. |
| March 10 | Belgian Congo Governor General Ryckman calls upon the colony to reestablish the balance of raw material supplies upset by the Japanese advance in the Dutch East Indies in a radio address from Leopoldville. A decree is issued authorizing forced labor of natives for 60 days annually to produce crops considerd necessary for the war effort. Natives in rubber producing areas required to turn in 60 lbs annually. |
| July | The British government reaches agreement with Belgian Colonial Ministry to purchase the Belgian Congo’s entire production of rubber, copper and gold. |
| August 30 | American troops arrive in Leopoldville to strengthen the Congo’s defenses. |
| August | The director of the Manhattan Project General Leslie Groves orders the purchase of 1250 tons of high quality Belgian Congo uranium ore stored on Staten Island by Union Minière du Haut Katanga. |
| | The first of 3,000 Greek refugees are settled in Ituri Province, Belgian Congo for the duration of the war. |
| November 10 | Royal Air Force No.349 Squadron is formed Ikeja, Nigeria, as a Belgian-manned fighter squadron for service in the Belgian Congo. |
| 1945 | July 10 | Civil aviation resumes. A Sabena Lockheed Lodestar arrives at Brussel’s Haren airfield from the Congo. |
| November 25 | An executive order creates advisory councils for the Belgian Congo and its provinces. The councils appointed by the Governor General are composed of missionaries, retired officials and a handful of natives. |
| 1946 | January 13 | Pan American Airways’ African Clipper departs New York on its inaugural flight to Leopoldville in the Congo. |
| January | The Belgian Congo Ambulance Corps returns to Leopoldville following wartime service in Ethiopia, Madagascar, India and Ceylon. |
| July 8 | Minister of Colonies Robert Godding calls for increased Belgian emigration to the Congo to establish the colony as a “national redoubt” in the event of another invasion. The Minister remarks on a drop in death rates for whites in the Congo from 22 to 7 per 1000 during the two decades preceding the war. |
| December 31 | Eugène Jungers succeeds Pierre Ryckmans as Governor General of the Belgian Congo. |
| 1948 | | Congolese workers are granted the right to strike and a legal minimum wage is established. |
| | The Fula-Fula, Léopoldville's first public transit system, is established using converted trucks as buses. |
| 1950 | April 4 | Polygamy is outlawed in the Belgian Congo. |
| During the Year | The Abako Party (Association des Bacongo) is formed. |
| | Simon Kimbangu founder of the Kimbanguists in the 1920s dies in prison. |
| 1951 | | The nationalist group Conscience Africaine is formed. |
| 1952 | January 1 | Léon Pétillon succeeds Eugène Jungers as Governor General of the Belgian Congo. |
| 1954 | | The Belgian Congo's first university, a branch of the University of Louvain, opens in Léopoldville. |
| 1955 | | King Baudouin visits the Belgian Congo and proposes formation of Belgian-Congolese Community. |
| | Premier van Bilsen introduces a 30 year plan and insists on the necessity of putting in place a federal structure that would be maintained by a Congolese elite that would gradually assume the levers of power. |
| | The Colonial Ministry opens three schools of public administration. |
| 1956 | | The Association Conscience Africaine rejects Belgian-Congolese Community concept and agrees to support the 30 Year Plan with the proviso that the Congolese be given a voice in its development. |
| | Abako demands the immediate institution of fundamental civil liberties. |
| | A branch of the University of Louvain is established in Elisabethville. |
| 1958 | July 12 | Henri Cornelis succeeds Léon Pétillon as Governor General of the Belgian Congo. |
| October | Patrice Lumumba founds the Congo National Movement to represent the country at the Pan-African Congress in Accra, Ghana. |
| During the Year | Municipal Councils are elected in Léopoldville, Elisabethville and Jadothville. |
| 1959 | January 4 | Rioting erupts in Léopoldville after a meeting of the Abako Party is prohibited. Forty two people are killed. |
| January 11 | The Government orders the Abako Party dissolved. |
| January 13 | King Baudouin announces that local elections by universal suffrage will be held in December with a view to preparing the Congolese for independence. |
| June 23 | Joseph Kasavubu, President of the Abako Party, demands creation of an independent Republic of the Congo in the western part of the Belgian Congo. |
| December | Martial law is declared in southern Kasai province following clashes between Lulua and Luba tribesmen. |
| | A coalition composed of Joseph Kasavubu's Abako Party, Antoine Gizenga's African Solidarity Party and the Congo National Movement of Albert Kaloji and Joseph Iléo demands talks with Brussels on the future status of the Belgian Congo. |
| During the Year | The Government legalizes the Kimbanguist Church of Jesus Christ on Earth by the Prophet Simon Kimbangu. |
| 1960 | January 29 | Belgian-Congolese round table negotiations set June 30 as the date of Congo's independence. |
| May 18 | The Belgian parliament approves an organic act establishing a constitution for the future independent state of the Congo. |
| May | Patrice Lumumba's Congo National Movement wins the country's first parliamentary elections. |
| June 24 | Patrice Lumumba is appointed Premier of the Congo. |
| June 30 | Govenor General Henri Cornelis hands power over to the Joseph Kasavubu, the first President of the Republic of the Congo. |
