Referred to by the French as Grande Comore, Ngazidja is the site of Moroni, the capital
city of the Republic, and is the largest of the islands in the Comoro archipelago. It has
an area of 442 square miles (1,146 square kilometers). The northern two-thirds of the
island are dominated by a rocky plain known as La Grille. The southern third of the
island is dominated by an active volcano, Karthala, which stands over 7700 feet (2361
meters) high. Karthala's crater is nearly a mile in diameter, making it the largest
active crater in the world. Since 1857 there have been over a dozen eruptions with lava
flows; the most extensive was that of 1918. The most recent serious eruption was in 1977.
The island's over 200,000 inhabitants are predominantly descended from Arab and African ancestors. Agriculture on the island is generally limited to areas lower than 2,000 feet in altitude. Above this altitude is the remnants of a dense tropical forest (in the south) and an area of grassy plain (in the center and north).
European sailing ships stopped for provisions at Ngazidja as early as 1570 when the island was ruled by 12 sultans. Although each was independent of the others, they generally recognized a principal sultan, whose rights and responsibilities were primarily conciliatory in inter-regional disputes, and accorded him or her the title of Sultan Thibe. There was frequent conflict over the right to use this title, especially after the Europeans appeared on the scene, as these latter generally assumed that the title indicated sovereignty over the entire island.
The best documented of the conflicts between sultans is the long and complicated struggle between the rulers of the towns of Bambao and Itsandra during the nineteenth century. This eventually led to the establishment of a French protectorate over the island and the ceding of Ngazidja to France.