Aceh Sultanate
Tribal warfare, although often motivated by resources, lands and slave grabbing, was also a tribal solution to settling disputes, as well as a component of coming of age rituals (headhunting) for several tribes, primarily the Dayak, Nias and Batak. Warriors from militaristic tribes were appreciated by other factions, and were recruited by developed kingdoms and polities as mercenaries, such as Nias warriors serving as palace guards in the Aceh Sultanate, as well as Ambonese warriors recruited by the Dutch East India Company.