The word Sadah or Sadat is a plural form of word سيد, while the wordBa 'Alawi or Bani 'Alawi means descendants of Alwi . In sum, Ba'alawi are Sayyids people who have a blood descendant of the Islamic prophetMuhammad through Alawi bin Ubaidullah bin Ahmad al-Muhajir. Meanwhile, Alawiyyin Sayyid term is used to describe descendants of Ali bin Abi Talib from Husain ibn Ali and Hasan ibn Ali. All people of Ba 'Alawi are Alawiyyin Sayyids through Husain ibn Ali, but not all people of Alawiyyin family are of Ba 'Alawi. The Ba 'Alawi tariqa is a sufi order founded by one of Ahmad al-Muhajir's descendant, Muhammad al-Faqih Muqaddam and named after and closely tied to the Ba 'Alawi family. Imam al-Muhajir's grandson Alawi was the first Sayyid to be born in Hadhramaut, and the only one of Imam al-Muhajir's descendants to produce a continued line; the lineages of Imam al-Muhajir's other grandsons, Basri and Jadid, were cut off after several generations. Accordingly, Imam Al-Muhajir's descendants in Hadhramaut hold the name Bā 'Alawi. The Ba 'Alawi Sadah have since been living in Hadhramaut in Southern Yemen, maintaining the Sunni Creed in the fiqh school of Shafii. In the beginning, a descendant of Imam Ahmad Muhajir who became scholar in Islamic studies was called Imam, then Sheikh, but later called Habib. It was only since 1700 AD they began to migrate in large numbers out of Hadhramaut across all over the globe, often to practice da'wah. Their travels had also brought them to the Southeast Asia. These hadhrami immigrants blended with their local societies unusual in the history of diasporas. For example, the House of Jamalullail of Perlis is descended from the Ba 'Alawi. Habib Salih of Lamu, Kenya was also descended from the Ba 'Alawi. In Indonesia, quite a few of these migrants married local women, sometimes nobility or even royal families, and their descendants then became sultans or kings, such as in Sultanate of Pontianak or in Sultanate of Siak Indrapura.
