| 1785 | | Sakalava slave traders from Madagascar begin raiding the Comoros. The islanders are carried off to be sold to French sugar plantations on Mauritius or Reunion. The island of Mohéli is virtually depopulated. Comoran pleas to the European powers for aid go unanswered. |
| 1802 | April 28 | General Jean Antoine Rossignol, deported, first to the Seychelles and later to the Comoros, for plotting to overthrow the Emperor Napoleon I dies at Mutsamudu on Anjouan. |
| 1808 | | Karthala, the 8,500 foot high volcano dominating Grande Comoro, erupts. It is the first of the mountain’s 20 eruptions over the next century. |
| 1816 | | The Sultan of Anjouan, Abdallah bin Alawi petitions the Governor of Reunion, General Bouvet de Lozier, requesting the protection of King Louis XVIII of France against Zanzibar pirates. |
| 1828 | | Ramanateka and a hundred of his Hova followers driven from Madagascar following the death of Radama I seek refuge on Mayotte. Sultan Boina Kombo bin Amadi allows them to settle on Moheli. Ramanteka seizes power on Moheli, converts to Islam and proclaims himself Sultan Abderahmane. |
| 1841 | | The Governor of Reunion, Vice Admiral Louis de Hell, dispatches Commandant Pierre Passot to Mayotte to negotiate a treaty of protection with the Sultan of Anjouan, Salim bin Alawi. |
| 1842 | | Queen Jumbe Fatima bint Abderremane of Moheli request French protection against Zanzibar. |
| 1843 | June 13 | France annexes the island of Mayotte. French Resident Pierre Passot establishes a headquarters on Zaudzi, an islet within the coral reef surrounding Mayotte. |
| 1846 | | Slavery is abolished on Mayotte. |
| 1848 | | A British consul is posted on Anjouan in an attempt to establish Great Britain as the prevailing European influence on the island. Ships of the Royal Navy begin to use the small anchorage at Pomony on the south side of the island as a coal depot. |
| 1856 | | Laborers on Mayotte rise up against harsh conditions imposed by Creole plantation owners. |
| 1865 | | French adventurer Joseph Lambert created Duke of Imerina by King Radama II of Madagascar journeys to Moheli where he obtains a concession to develop nearly all the land on the island from Queen Jumbe Fatima bint Abderremane. |
| ca. 1872 | The British India Steam Navigation Company’s steamer to Zanzibar begins collecting mail in the Comoros. 1878 |
| | Joseph Lambert dies. Moheli falls into a state of anarchy worsened by concurrent French and British maneuvering for influence. |
| 1880 | | French steamers link Mayotte with Reunion via Nossi Be. |
| 1882 | | Sultan Saidi Abdallah bin Salim turns to France for protection after Great Britain attempts to gain the abolition of slavery on Anjouan. |
| 1883 | | Leon Humblot, sent by the Museum of Natural History of Paris to study the flora and fauna of the Indian Ocean islands, signs a treaty with the Sultan Said Ali of Bambao on Grande Comoro granting him as much land as he can develop and workers in return for 10% of the profits. |
| 1885 | | La Compagnie Messageries Maritimes’ Colonial Line links the Comoros with Madagascar. Hachimu bin Mugné Mku seizes power from Queen Khadija binti Mugné Mku of Badgini on Grande Comoro. Hachimu tries to convince the French declare Badgini a protectorate separate from Grande Comoro. The French refuse. They declare Hachimu to be in revolt against Sultan Saidi Ali of Grande Comoro and refuse to recognize him as Sultan of Badgini. |
| 1886 | April 21 | Saidi Abdallah bin Salim Sultan of Anjouan accepts a French protectorate. |
| April 26 | Sultan Mohammed Shekhe of Moheli accepts a French protectorate. |
| June 24 | The Sultan of Grande Comoro Saidi Ali bin Saidi Omar accepts a French protectorate. |
| During the Year | Hachimu bin Mugné Mku attempts to place Badgini under the protection of the German East Africa Company. The Company initially accepts the proposition but backs out when its agent, Karl Wilhelm Schmidt, discovers that Hachimu is a rebel fighting an existing French protectorate. |
| 1889 | November | Leon Humblot is named French Resident on Grande Comoro. He establishes La Société Anonyme de la Grande Comore, a concessionary company specializing coconuts and fragrant blossoms particularly those of the peppery Ylang Ylang. Humblot’s company gradually spreads throughout the archipelago and forms a network of vertically integrated agricultural enterprises which eventually gain a near monopoly on economic activity in the islands. 1891 |
| | April 23 – July 16 French Marines of the Indian Ocean Fleet land on Anjouan to quell a revolt against Sultan Saidi Omar bin Saidi Hasan. |
| | August 16 – November 19 French Marines of the Indian Ocean Fleet land on Grande Comoro to quell a revolt. |
| 1892 | | The Iles Glorieuses, three islets 255 kilometers north of Mayotte , are annexed by France and placed under the authority of the Governor of Mayotte. The population of about 20 is engaged in the collection of guano and the capture of sea turtles. |
| 1898 | | A severe cyclone devastates Mayotte. |
| 1902 | | A post office is opened on Moheli. |
| 1907 | | La Société Coloniale de Bambao is formed to operate concessions on the lands of the Sultan of Anjouan. |
| 1908 | April 9 | The Comoro Islands are placed under the supreme authority of the Governor General of Madagascar. Local administration remains in the hands of the French Resident on Mayotte. |
| 1909 | | A French court rules the 1892 ouster of Saidi Ali as Sultan of Grande Comoro illegal. He is not allowed to return to power and force to accept financial compensation. |
| 1910 | February 3 | The Sultan of Grande Comoro Saidi Ali bin Saidi Omar visits France and formally cedes his sovereign rights to France. |
| During the Year | The population of the Comoros numbers some 82,000 including 600 Europeans and 200 Indians. |
| 1912 | July 25 | Anjouan is annexed by France as a colony. |
| 1914 | February 23 | The Comoros are made a dependency of Madagascar. |
| During the Year | Leon Humblot, former French Resident and the business magnate of Grande Comoro, dies. |
| 1915 | | The residents of Oichili on Grande Comoro refuse to accept the imposition of a Malagasy village chieftain. |
| June - August | The natives of Mboudé on Grande Comoro refuse to pay a head tax. The revolt is crushed by troops from Madagascar and the leaders are exiled. |
| 1916 | February 10 | Saidi Ali bin Saidi Omar, the last reigning Sultan of Grande Comoro, dies at Tamatave on Madgascar. |
| August 4 | Said Houssein, the son of Grande Comoro’s last reigning sultan, volunteers for service in the French Foreign Legion. |
| 1923 | | The Spanish Influenza strikes the Comoros. |
| | The post of Chief Administrator for the Comoros seated at Dzaoudzi on Mayotte is created. |
| 1925 | July 1 | The Madagascar Franc issued by the Bank of Madagascar is introduced as the legal tender currency of the Comoros. |
| 1926 | | The first native Comorian doctor, Said Mohamed Sheik, graduates from the School of Medicine at Tananarive. |
| 1938 | | La Société Anonyme de la Grande Comore absorbs La Société Coloniale de Bambao. |
| 1939 | | There are 10 primary schools in the islands but only five secondary school students who travel to Madagascar to continue their education. |
| October 25 | Great War veteran Said Houssein, the son of Grande Comoro’s last reigning sultan, returns to the ranks. |
| 1940 | | Laborers conscripted for work in the field on Anjouan stage a short lived rebellion. |
| June | The French administration in the Comoros remains loyal to Vichy. |
| 1942 | July 2 | British troops seize Mayotte where they construct a seaplane base. |
| September 25 | British troops occupy the Comoros and oust the Vichy administration. |
| 1943 | May | Administration of civil affairs on the Comoros is turned over to the Free French. |
| 1945 | | Said Mohamed Sheik is elected to represent the Comoros in the French Constituent Assembly. |
| 1946 | May 9 | The Comoros are made an overseas territory of France. |
| October 13 | British forces withdraw from the Comoros. |
| 1947 | | The Comoros are granted representation in the French National Assembly. |
| 1950 | | The first secondary school in the Comoros opens at Moroni on Grande Comoro. |
| 1953 | | General de Gaulle visits the Comoros. |
| 1956 | June 23 | The Defferre Law grants a measure of autonomy to the Comoros and creates a Council of Government at Dzaoudi on Mayotte and an Assembly sitting at Moroni on Grande Comoro. |
| 1958 | September 28 | The Comoros approve a referendum on the Constitution of the Fifth Republic and the French Community. |
| 1961 | December 22 | The Comoros are granted full internal autonomy. France retains control of the islands’ foreign relations, defense and judicial system. |
| 1973 | January 15 | A Franco-Comoran accord to grant the islands independence within 5 years subject to a plebiscite is signed in Paris. |
| 1975 | July 6 | The Comoros Assembly declares unilateral independence. |
| December 31 | France recognizes the independence of Grand Comoro, Anjouan and Moheli where a majority of the inhabitants are Moslem. |
| 1976 | February | Mayotte’s Catholic majority votes to remain a French overseas department. |
