At the beginning of the twentieth century control over the vast area of mainland and islands now known as South-East Asia was almost monopolised by the Netherlands, Britain, France and the United States of America. Of the four the Dutch had been established the longest and possessed by far the richest empire. With its centre at Batavia, founded by Jan Pieterszoon Coen in 1619, Netherlands India, the ‘girdle of emerald flung round the equator’, comprised the whole Malay archipelago except the Philippines, newly acquired from Spain by the United States (Treaty of Paris, December 1898), north-western Borneo, the Portuguese half of Timor, and eastern New Guinea, the northern part of which was in German possession, the southern a British colony. The Netherlands Indies stretched for nearly three thousand miles from the north-west point of Sumatra to the eastern limit of Dutch territory in New Guinea, its breadth from north to south was roughly thirteen hundred miles, and it had a total land area of nearly 735,000 square miles. In 1900 the reduction of the whole area to Dutch rule was still incomplete. Much of it had been acquired only in the second half of the nineteenth century. The Achinese of north-west Sumatra, who had been fighting for independence since 1873, were not to be finally brought under control until 1908.