A culture of violence rooted in the deep conflicts that split the countryside during the revolution would repeatedly erupt throughout the whole second half of the 20th century. The term 'social revolution' has been applied to a range of mostly violent activities of the left that included both altruistic attempts to organise real revolution and simple expressions of revenge, resentment and assertions of power. Violence was one of the many lessons learned during the Japanese occupation, and figures identified as 'feudal', including kings, regents, or simply the wealthy, were often attacked and sometimes beheaded. Rape became a weapon against 'feudal' women. In the coastal sultanates of Sumatra and Kalimantan, for example, sultans and others whose authority had been shored-up by the Dutch, were attacked as soon as Japanese authority left. The secular local lords of Aceh, who had been the foundation of Dutch rule, were executed, although most of Indonesia's sultanates fell back into Dutch hands.