Ceremonial cotton cloth of the Lampung ethnic group of southern Sumatra
Courtesy Museum Nasional Indonesia and Festival of Indonesia

The vast, heavily forested island of Sumatra forms the southern perimeter of the Strait of Malacca. The strait is one of the most important lanes of shipping and commerce in the world, and historically a crossroads of cultural influences from the Middle East, India, China, and elsewhere in Southeast Asia and East Asia. Although nearly all of the approximately twenty ethnolinguistic groups of Sumatra are devout practitioners of Islam, they nonetheless differ strikingly from one another, particularly in their family structures.

Data as of November 1992