Sundarbans, large, heavily forested swamp region, c.3,860 sq mi (10,000 sq km), in the S Ganges delta on the Bay of Bengal, about 60% in SW Bangladesh and the rest in West Bengal state, India. The more than 100 low, marshy islands and many tidal rivers and creeks of the Sundarbans are home to the world's largest mangrove forest, which is inhabited by a wide variety of animal life including tigers, water buffalo, crocodiles, pythons, and many species of birds and aquatic life. Rice is grown, mainly in the east, and coconut palms in the west; the main trade center is Khulna in Bangladesh. The village of Iswaripur, Bangladesh, was the capital of an independent 16th-century Muslim kingdom, which was ravaged by the Arakanese (Rakhine) and by Portuguese pirates in the 18th cent.
By the early years of the 21st cent. extensive tree-felling had destroyed more than half of the mangrove forest in the Indian Sundarbans, and the region's islands were in ecological peril from rising sea levels and widespread erosion. Over three decades some 31 sq mi (90 sq km) of land has been lost (several islands completely disappeared), and many island inhabitants displaced. The region also is subject to frequent cyclones (hurricanes); in Nov., 2007, for example, Cyclone Sidr destroyed some 590 sq mi (1,528 sq km) of forest in the SW Sundarbans.