military coup in Portugal and the subsequent rise of dictator António de Oliveira Salazar saw racial categories becoming fully codified, separating the bulk of the native population, who were designated as uncivilised, from the white settlers, mestiços, and the assimilados (natives considered to have become civilised and assimilated). The colony was seen as an economic burden during the Great Depression, and received little support or management from Portugal. In the 1930s, the Japanese semi-governmental Nan'yō Kōhatsu development company, with the secret sponsorship of the Imperial Japanese Navy (IJN), invested heavily in a joint-venture with the primary plantation company of Portuguese Timor, SAPT. The joint-venture effectively controlled imports and exports into the island by the mid-1930s and the extension of Japanese interests greatly concerned the British, Dutch and Australian authorities. World War II Although Portugal was neutral during World War II, in December 1941, Portuguese Timor was occupied by a small British, Australian and Dutch force, to preempt a Japanese invasion. However, the Japanese did invade in the Battle of Timor in February 1942. Under Japanese occupation, the borders of the Dutch and Portuguese were overlooked with Timor island being made a single Imperial Japanese Army (IJA) administration zone. Because of Portugal's neutrality, the Japanese left the Portuguese governor in place and in formal control of Liquiçá. 400 Australian and Dutch commandos trapped on the island by the Japanese invasion waged a guerrilla campaign in the mountainous interior, the Battle of Timor, which tied up Japanese troops and inflicted over 1,000 casualties. Timorese and the Portuguese helped the guerillas but following the Allies' eventual evacuation, Japanese retribution from their soldiers and Timorese militia raised in Dutch Timor was severe. By the end of the War, an estimated 40–60,000 Timorese had died, the economy was in ruins, and famine widespread. Post-WW2 Following World War II, the Portuguese promptly returned to reclaim their colony, while Dutch Timor became part of Indonesia as Indonesian Timor, when it secured its independence in 1949. Keen to maintain its colonies under the ideology of Lusotropicalism, Portugal formally declared Timor as an Overseas province. A small increase in education, infrastructure, and health development was coupled with increased repression. The international pressure for decolonisation and unrest in Portuguese Africa had little impact internally in Portuguese Timor, where identities remained linked to local kingdoms. To rebuild the economy, colonial administrators forced local chiefs to supply labourers which further damaged the