This article undertakes first a reconstruction of lists of legal scribes (kātibs) and investigators (ṣāḥibs al-masāʾil ) active in Fusṭāṭ between the 1st/early 8th and the 4th/10th century. Identification of these people allows a better understanding of the recruitment of Egyptian judiciary staff. Their reputations as scholars, as well as their ethnical, geographical and tribal origins, show that legal careers were limited by social barriers for a long time. Up until the 3rd/9th century, the office of scribe was mostly held by mawālī—high-ranking clients could possibly aspire to the office of investigator—, whereas qāḍīs were recruited among Arabs. The partitioning of the judiciary reveals a complex social hierarchy beyond the mere distinction between Arabs and non-Arabs. The results of this study also allow a re-evaluation of the Abbasid revolution’s impact on Egyptian society.