(1821–37), armed conflict in Minangkabau (Sumatra) between reformist Muslims, known as Padris, and local chieftains assisted by the Dutch. In the early 19th century the puritan Wahhābīyah sect of Islām spread to Sumatra, brought by pilgrims who entered the island through Pedir, a northern port. The Padris, as these Sumatran converts to Wahhābīyah came to be known, objected to local institutions that were not in accordance with the pure teaching of Islām. This jeopardized the power of the local chiefs, whose authority was based on adat, or customary law. In the ensuing conflict between the Padris and local chiefs, the Padris, using Bondjol as their base, launched guerrilla war against the chiefs. The Dutch, afraid of the influence of the Muslim reformists, sided with the chiefs but were still engaged in the Java War (1825–30) and thus unable to send troops to crush the Padris until the end of that war. Tuanku Imam Bondjol, the leader of the Padris, surrendered to the Dutch in 1832 but soon renewed his rebellion. The war continued until 1837, when the Dutch seized Bondjol. The war allowed the Dutch to extend their control into the interior regions of Sumatra.