For ten points, identify this middle ages term used to describe those who followed Islam.
Early use of this term was used by Europeans to describe the Fatmid Caliphate. Eventually, this Arabic-derived word meaning easterners was used after crusaders made their way back to Western Europe. In Christian writing, this term was thought to mean empty of Sarah or not from Sarah in reference to Muslims being descended from Hagar, Ishmael's mother. For ten points, identify this middle ages term used to describe those who followed Islam.
Early use of this term was used by Europeans to describe the Fatmid Caliphate.
Saracen