Due to an influx of immigrants and guest workers from India, the Philippines and Sri Lanka, the overall percentage of Muslims has declined since the late 20th century.
[7] The origins of Shia Islam in Bahrain can be traced back to 656–661 AD, the caliphate reign of Ali ibn Abi Talib.
The Islamic prophet Muhammad appointed Aban Ibn Sa'id Al As (Arabic: أبان ابن سعيد العاص) as governor of Bahrain during his lifetime.
Aban was a major supporter of Ali's right to the caliphate, a position that was endorsed by the inhabitants of Bahrain including the influential Bani Abdul Qays tribe.
They raided Iraq and in 930 sacked Mecca, desecrating the Zamzam Well with the bodies of Hajj pilgrims and taking the Black Stone with them back to Bahrain where it remained for twenty years.
In the 2006 election Wefaq received the backing of the Islamic Scholars Council which helped it win seventeen of the eighteen seats it contested.