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Al-ʿAlāʾ al-Haḍramī (Arabic: العلاء الحضرمي) was a Haḍramī envoy sent by Muhammad in the 7th century CE to spread Islam to the region that extends from Kuwait to Ras al-Khaimah. He was from Hadhramaut in Yemen.
Prior to Islam, the inhabitants of the region of Bahrain were mostly pagans who worshipped idol gods like Awal, and there were also some Zoroastrians and Jews. Islam swept the Arabian peninsula in the 7th century, overturning the idol worshippers. Muhammad sent his first envoy Abu Al-Ala'a Al-Hadrami to Munzir ibn Sawa Al Tamimi, the ruler of Bahrain, which in those days, extended the coast from Kuwait to the north of Oman including al-Hasa and Bahrain Islands, in the year 628 AD, inviting him and the Abdul Qays tribe to Islam. Munzir, responding to Muhammad's call announced his conversion to Islam and all the Arab inhabitants of the region of Bahrain including some Persians living in the region also became Muslim, heralding the beginning of the Islamic era in the region of Bahrain. Consequently, Abu Al Ala Al-Hadrami was appointed by Muhammad as his representative in Bahrain to collect the Jizya (religious tax).
After the death of Muhammad in 632 AD, large numbers of Arab tribes revolted against the Islamic empire, including a large portion of Bahrain's population who returned to paganism. As a result, the new Caliph Abu Bakr sent Al-Hadrami back to Bahrain with a sizeable army where he successfully defeated the rebels. He governed Bahrain until 634 AD when the new Caliph Umar replaced him with Uthman ibn Abi al-As  after he failed in the first naval invasion to Fars. Al Hadrami later died in 635 AD and was buried in modern day Hawali, Kuwait.
There are multiple streets and a school named after Al-Hadrami in Bahrain. The letter from Muhammad to Munzir ibn Sawa Al Tamimi is preserved and can be seen at Beit Al Qur'an museum in Hoora, Bahrain, with the seal of Muhammad still intact.