Judah ben Joseph b. Simḥa was perhaps the most important figure in the Jewish community of Qayrawān toward the end of the tenth century and the beginning of the eleventh. Known in Arabic as Abū Zikrī/Zakarīyāʾ (the usual kunya for the name Judah), he was one of the wealthiest merchants in Qayrawān and was on very good terms with the Zirid sultan of Tunisia, al-Muʿizz ibn Bādīs (r. 1016–1062), and especially with the young sultan’s influential aunt Umm Mallāl, who, if indeed “the illustrious mistress” (Ar. al-sayyida al-jalīla) mentioned by Judah in a letter written toward the end …