Although time frames for the establishment of Islam in Indonesian regions can be broadly determined, the historical primary sources cannot answer many specific questions, and considerable controversy surrounds the topic. Such sources do not explain why significant conversions of Indonesians to Islam did not begin until after several centuries of foreign Muslims visiting and living in Indonesia, nor do they adequately explain the origin and development of Indonesia's idiosyncratic strains of Islam, or how Islam came to be the dominant religion in Indonesia.[1]:8 To fill these gaps, many scholars turn to Malay and Indonesian legends surrounding Indonesian conversion to Islam.