The history of the arrival and spread of Islam in Indonesia is a little unclear despite it being one of the most significant developments in Indonesian history as there are many competing theories and only fragmentary historical evidence. One theory states it arrived directly from Arabia before the 9th century, while another credits Sufi merchants and preachers for bringing Islam to Indonesian islands in the 12th or 13th century either from Gujarat, India or directly from the Middle East.

This episode is also available as a blog post: http://martinifisher.com/2020/06/05/spread-of-islam-and-introduction-to-the-javanese-philosophy/