Al-Baghdadi is sometimes known as Ibn Tahir. His full name is Abu Mansur Abr al-Qahir ibn Tahir ibn Muhammad ibn Abdallah al-Tamini al-Shaffi al-Baghdadi. We can deduce from al-Baghdadi’s last two names that he was descended from the Bani Tamim tribe, one of the Sharif tribes of ancient Arabia, and that he belonged to the Madhhab Shafi’i school of religious law.

http://www-history.mcs.st-andrews.ac.uk/Biographies/Al-Baghdadi.html