Irian Jaya Irian Jaya is Indonesia's "wild east". Much of it was still unexplored by outsiders in the 1930s. The Dutch began serious exploration in about 1898. After the Indonesians defeated the Dutch in 1949 and 1950, the Dutch insisted on keeping Irian Jaya. They finally gave up the colony in 1963, under a combination of military and diplomatic pressure. In 1969, a UN-sponsored referendum led to Irian Jaya becoming a province of Indonesia. Jayapura is the main city. It was formerly called Hollandia by the Dutch. Allied (American and Australian) forces passed through here in 1944 on the way to the reconquest of the Philippines.