Substantial written references to the Gayo only begin in the late nineteenth century. It is likely, however, that the Gayo homeland belonged to the Islamic kingdom of Aceh in the seventeenth century and that Islamization of the area had begun by that time. At the outbreak of the Aceh-Dutch war in 1873, Gayo possessed a strong sense of ethnic distinctiveness but recognized a nominal Acehnese suzerainty. Some Gayo continued to resist the Dutch after the invasion of the highlands in 1904. During Dutch occupation (1904-1942) Gayo developed a thriving cash-crop economy in vegetables and coffee, attained a relatively high level of basic education, and participated in the movements of Islamic modernism and Indonesian nationalism. Gayo fought to maintain Indonesian independence (declared in 1945) and participated in the provincial Darul Islam rebellion against the central government (1953-1962). Gayo took part in the postcoup massacres (GESTAPU) of 1965-1966 and, unlike most of Aceh, voted for the government party, GOLKAR, in the 1970s and 1980s.