Muhammad sent Al-Ala'a Al-Hadrami, a Muslim envoy, to a Persian ruler in Eastern Arabia named Munzir ibn Sawa Al Tamimi in 628 and requested that he and his people accept Islam. Munzir obliged his request and most Arab tribes in Qatar converted to Islam. It has been proposed by historian Habibur Rahman that Munzir ibn Sawa's seat of administration existed in the Murwab or Umm al-Ma'a area of Qatar. This theory is lent credence by an archaeological find of approximately 100 small stone-built Islamic-period houses and fortified palaces of a tribal leader in Murwab, which are thought to have originated from the early Islamic period. After the adoption of Islam, the Arabs led the Muslim conquest of Persia which resulted in the fall of the Sasanian Empire.