CHAGOS, an archipelago in the Indian ocean, belonging to Great Britain and administered by Mauritius, set around the Chagos bank (circumference c. 270m.), in 44' to 39' S., and 55' to 72° 52' E. Total land area, 76 square miles. The atolls on the south and east side of the bank have disappeared through subsidence; a few—Egmont, Danger, Eagle and Three Brothers— still remain, but most of the population (445 in 1921, a large pro portion being negro labourers from Mauritius) is centred on Diego Garcia, which lies on the south-east side, and is nearly 13m. long by 6m. wide. The lagoon is enclosed by two coral barriers and is accessible to the largest vessels on the north side. The French occupied the islands in 1 791 from Mauritius, and the oil industry (from which the group is sometimes called the Oil islands) came into the hands of French Creoles. In 1814 Mauri tius and its dependencies were ceded to England. Large quantities of coconut oil are exported annually (over 134,000gals. in 1925 against I oo,000gal. per ann. 20 years ago) . Other exports are coconuts, copra, guano and salted fish.