As of 2016, Islam is the dominant religion in the province, forming 77.56% of the total population. Islam is generally adhered by the ethnic Malays, Javanese, Minangkabau, Banjars, Bugis, Sundanese and some Batak sub-group. Islam has entered the region since at least the 12th century. Contact between the indigenous population and Muslim traders from the Arabian Peninsula, Persia and India did occur for the first time in the northern Sumatra region because of its strategic position to traders stopover at that time. This condition strengthens the indication that the Islamization process is expected to have taken place since the contact took place so that a community was formed where the Arabs who settled in the village were married to local residents thus forming Muslim communities. Islam is generally adhered by the ethnic Malays, Javanese, Minangkabau, Banjars, Bugis, Sundanese and some Batak sub-group. Several Muslim organizations in Indonesia has branches in the Riau Islands, such as Muhammadiyah and the Nahdlatul Ulama.