Nahray ben Nissim (ca. 1025-1098), nicknamed Abū Yaḥyā, was a North African merchant and communal leader. More than 350 letters, notes, and accounts from the Cairo Geniza are either addressed to him or emanate directly from his hand, comprising the largest corpus of documentary sources from the Geniza concerning a single individual.

Born around 1025 and descended from a leader (nagid) of the Qayrawan community, Nahray migrated to Egypt around 1040, where he entered the patronage of his relative Barhūn b. Isḥaq Tahertī. At the center of a network of traders plying the Mediterranean …