The Achinese War was a war between Dutch colonial forces and the Muslim kingdom of Achin in northern Sumatra, lasting from 1873 to 1904. By the Sumatra Treaty of 1871, the British recognised Dutch hegemony over Sumatra in return for Dutch claims to the Gold Coast, Africa. The Dutch subsequently moved against the Achinese in 1873, who had long resisted Dutch control and were actively engaged in piracy. The Dutch defeated the sultan of Achin that year, but local leaders carried on a protracted and costly guerrilla war, which lasted until 1904. Research Achinese War