Other Indonesian areas gradually adopted Islam, making it the dominant religion in Java and Sumatra by the end of the 16th century. For the most part, Islam overlaid and mixed with existing cultural and religious influences, which shaped the predominant form of Islam in Indonesia, particularly in Java. Only Bali retained a Hindu majority. In the eastern archipelago, both Christian and Islamic missionaries were active in the 16th and 17th centuries, and, currently, there are large communities of both religions on these islands.