By the early 19th century, Islam had come to be the religious element in Javanese identity, but it was a particular kind of Islam described by the author as a “mystic synthesis”. The Javanese held firmly to their identity as Muslims and fulfilled the basic ritual obligations of the faith, but they also accepted the reality of local spiritual forces. Polarising Javanese Society discusses how colonial rule, population pressure and Islamic reform undermined this distinctively Javanese syncretism. A fourfold division appeared among pious Muslims -- some remained adherents of the “mystic synthesis”, some followed reformers who demanded a more orthoprax way of life, some supported reformist Sufis, and some accepted messianic ideas. A new category emerged comprising Javanese who resisted Islamic reform and began to attenuate their Islamic identity. These increasingly nominal Muslims -- the majority -- became known as abangan. The priyayi elite meanwhile embraced the forms of modernity as represented by their European rulers and modern scientific learning, and Christianity began to make limited inroads into Javanese society. Some even came to regard the original conversion of the Javanese to Islam as a civilisational mistake, and within this social element explicitly anti-Islamic concepts took shape. In the early 20th century, these categories became politicised in the context of Indonesia’s nascent anti-colonial movements. Thus were born the contending political identities that lay behind much of the conflict and bloodshed of 20th-century Indonesia. Based on a wide range of original sources in Javanese and Dutch, this book is the first thoroughly researched publication on Islam in Java.