The Mustaali line split again between the Taiyabi (Dawoodi Bohra is its main branch) and the Hafizi. The former claim that At-Tayyib Abi l-Qasim (son of Al-Amir bi-Ahkami l-Lah) and the imams following him went into a period of anonymity ("Dawr-e-Satr") and appointed a Da'i al-Mutlaq to guide the community, in a similar manner as the Ismaili had lived after the death of Muhammad ibn Ismail. The latter (Hafizi) claimed that the ruling Fatimid Caliph was the Imam, and they died out with the fall of the Fatimid Empire.