Complex sentence: The "mashad" is a characteristic type of Fatimid building, a shrine that commemorates a descendant of the Prophet Muhammad, and the tombs of the Fatimid caliphs were also treated as shrines.
Split into simpler sentences: The "mashad" is a characteristic type of Fatimid building, a shrine that commemorates a descendant of the Prophet Muhammad. The tombs of the Fatimid caliphs were also treated as shrines.