Exploiting such conflicts, the Dutch then took advantage of the opportunity to reduce the indigenous powers to a state of dependence. Not until the third quarter of the 18th century, did the Dutch gradually succeed making the kingdom of Mataram, Banten and to a certain degree Cirebon in Java vassals of the VOC. Moreover, in Java they gained economic control over the most productive areas of this island by means of tax levies and many kinds of tribute from their vassals. The VOC also introduced new crops such as coffee. In so doing, they gradually transformed their system into a Java-based polity, concentrating more and more on the exploitation of natural resources of Java, while their maritime power and grip on trade in the Outer Islands areas declined until its bankruptcy in 1799.
Entering the 19th century, Java became increasingly the center of political and economic activities of the Dutch in the Indonesian archipelago. In the second quarter of the 19th century, the Dutch colonial government opened up several ports in the Outer Islands as free ports for international trade. Nevertheless, the production potential of the Outer Islands could not be easily recovered. At the same time, the Dutch colonial government focused on the establishment of infrastructure in Java, building such things as roads, railways, telegraphs, bridges, and irrigation systems in order to encourage Java to produce more profitable commodities for the European market. The implication of this policy was that the Outer Islands were ignored, while Java was increasingly developed as the favorite. Batavia was projected to become the centre of shipping and trade in Southeast Asia, first competing with and then replacing the role of Malacca
as the center of the previous Malay world