Complex sentence: There are various spurious theories about the origins of the Khattars--one is they are Non-Fatimid Arabs, descended from Ali, cousin and son-in-law of the Islamic prophet Muhammad, and thus an Arab tribe that entered in Spain with Tariq Bin Ziyad.
Split into simpler sentences: There are various spurious theories about the origins of the Khattars--one is they are Non-Fatimid Arabs, descended from Ali, cousin and son-in-law of the Islamic prophet Muhammad. Being an Arab tribe that entered in Spain with Tariq Bin Ziyad.