COMORO ISLANDS, a group of volcanic islands belonging to France, in the Indian Ocean, at the northern entrance of the Mozambique Channel midway between Madagascar and the African continent. The following table of the area and population of the four largest islands gives one of the sets of figures offered by various authorities:—
| Area sq. m. | Population. | |
| Great Comoro | 385 | 50,000 |
| Anjuan or Johanna | 145 | 12,000 |
| Mayotte | 140 | 11,000 |
| Moheli | 90 | 9,000 |
| Total | 760 | 82,000 |
There are besides a large number of islets of coral formation. Particulars of the four islands named follow.
1. Great Comoro, or Angazia, the largest and most westerly, has a length of about 38 m., with a width of about 12 m. Near its southern extremity it rises into a fine dome-shaped volcanic mountain, Kartola (Karthala), which is over 8500 ft. high, and is visible for more than 100 m. Up to about 6000 ft. it is clothed with dense vegetation. Eruptions are recorded for the years 1830, 1855 and 1858; and another eruption occurred in 1904. In the north the ground rises gradually to a plateau some 2000 ft. above the sea; from this plateau many regularly shaped truncated cones rise another 2000 ft. The centre of the island consists of a desert field of lava streams, about 1600 ft. high. The chief towns are Maroni (pop. about 2000), Itzanda and Mitsamuli; the first, situated at the head of a bay in 11° 40′ S., being the seat of the French administrator.
2. Anjuan, or Johanna, next in size, lies E. by S. of Comoro. It is some 30 m. long by 20 at its greatest breadth. The land rises in a succession of richly wooded heights till it culminates in a central peak, upwards of 5000 ft. above the sea, in 12° 14′ S., 44° 27′ E. The former capital, Mossamondu, on the N.W. coast, is substantially built of stone, surrounded by a wall, and commanded by a dilapidated citadel; it is the residence of the sultan and of the French administrator. There is a small but safe anchorage at Pomony, on the S. side, formerly used as a coal depot by ships of the British navy.
3. Mayotte, about 21 m. long by 6 or 7 m. broad, is surrounded by an extensive and dangerous coral reef. The principal heights on its extremely irregular surface are: Mavegani Mountain, which rises in two peaks to a maximum of 2164 ft., and Uchongin, 2100 ft. The French headquarters are on the islet of Zaudzi, which lies within the reef in 12° 46′ S., 45° 20′ E. There are substantial government buildings and store-houses. On the mainland opposite Zaudzi is Msapéré, the chief centre of trade. Mayotte was devastated in 1898 by a cyclone of great severity.
4. Moheli or Mohilla lies S. of and between Anjuan and Grand Comoro. It is 15 m. long and 7 or 8 m. at its maximum breadth. Unlike the other three it has no peaks, but rises gradually to a central ridge about 1900 ft. in height. Fomboni (pop. about 2000) in the N.W. and Numa Choa in the S.W. are the chief towns.
All the islands possess a very fertile soil; there are forests of coco-nut palms, and among the products are rice, maize, sweet-potatoes, yams, coffee, cotton, vanilla and various tropical fruits, the papaw tree being abundant. The fauna is allied to that of Madagascar rather than to the mainland of Africa; it includes some land birds and a species of lemur peculiar to the islands. Large numbers of cattle and sheep, the former similar to the small species at Aden, are reared as well as, in Great Comoro, the zebra. Turtles are caught in abundance along the coasts, and form an article of export. The climate is in general warm, but not torrid nor unsuitable for Europeans. The dry season lasts from May to the end of October, the rest of the year being rainy. The natives are of mixed Malagasy, Negro and Arab blood. The majority are Mahommedans. The European inhabitants, mostly French, number about 600. There are some 200 British Indians, traders, in the islands. The external trade of the islands has developed since the annexation of Madagascar to France, and is of the value of about £100,000 a year. Sugar refineries, distilleries of rum, and sawmills are worked in Mayotte by French settlers. Cane sugar and vanilla are the chief exports. The islands are regularly visited by vessels of the Messageries Maritimes fleet, and a coaling station for the French navy has been established.
The islands were first visited by Europeans in the 16th century; they are marked on the map of Diego Ribero made in 1527. At that time, and for long afterwards, the dominant influence in, and the civilization of, the islands was Arab. According to tradition the islands were first peopled by Arab voyagers driven thither by tempests. The petty sultans who exercised authority were notorious slave traders. A Sakalava chief who had been driven from Madagascar by the Hovas took refuge in Mayotte c. 1830, and, with the aid of the sultan of Johanna, conquered the island, which for a century had been given over to civil war. French naval officers having reported on the strategic value of Mayotte, Admiral de Hell, governor of Réunion, sent an officer there in 1841, and a treaty was negotiated ceding the island to France. Possession was taken in 1843, the sultan of Johanna renouncing his claims in the same year. In 1886 the sultans of the other three islands were placed under French protection, France fearing that otherwise the islands would be taken by Germany. The French experienced some difficulty with the natives, but by 1892 had established their position. The islands, as regulated by the decree of the 9th of April 1908, are under the supreme authority of the governor-general of Madagascar. The local administration is in the hands of an official who himself governs Mayotte but is represented in the other islands by administrators. On the council which assists the governor are two nominated native notables. In 1910 the sultan of Great Comoro ceded his sovereign rights to France. In Anjuan the native government is continued under French supervision. The budgets of the four islands in 1904 came to some £30,000, that of Mayotte being about half the total. The chief sources of revenue are poll and house taxes, and, in Mayotte, a land tax.
The Iles Glorieuses, three islets 160 m. N.E. of Mayotte, with a population of some 20 souls engaged in the collection of guano and the capture of turtles, were in 1892 annexed to France and placed under the control of the administrator of Mayotte.
See Notice sur Mayotte et les Comores, by Emile Vienne, one of the memoirs on the French colonies prepared for the Paris Exhibition of 1900; Le Sultanat d’Anjouan, by Jules Repiquet (Paris, 1901), a systematic account of the geography, ethnology and history of Johanna; Les colonies françaises (Paris, 1900), vol. ii. pp. 179-197, in which the story of the archipelago is set forth by various writers; an account of the islands by A. Voeltzkow in the Zeitschrift of the Berlin Geog. Soc. (No. 9, 1906), and Carte des Iles Comores, by A. Meunier (Paris, 1904).