For centuries the Batak lived a way of life which developed largely in isolation. Their bloody feuds and guerrilla attacks on each other's villages gained them an apparently well-earned reputation for ferocity, although they also had a remarkably developed culture as well as a system of writing. They also practised ritual cannibalism in which a token piece of flesh - of a slain enemy or of one judged guilty of a major violation of traditional laws - was eaten. The heads and hands of war captives were sometimes preserved as trophies.
Bataks are also renowned for their traditional architecture - houses built on stilts around two metres above the ground. The houses are made of wood, slotted and bound together without nails, with a concave roof made from sugar palm fibre. The gables of the roof are embellished with mosaics and carvings. Today there are more than six million Bataks, and their lands extend 200km north and 300km south of Danau Toba. Many Bataks have now converted to Islam or Christianity.