Chapter 4 examines the surviving nomocanonical manuscripts from the period of Byzantine rule in early medieval southern Italy (tenth–eleventh centuries). Very few manuscripts survive from before the twelfth century, so their content must be reconstructed from later codices. Nonetheless, this chapter argues that enough evidence has been preserved to prove that Byzantine canon law was firmly established in southern Italy from the time of the empire’s ecclesiastical and administrative reorganisations of the ninth and tenth centuries. The chapter shows that, as the Byzantines reconquered territories from the Lombards and established new ecclesiastical centres in Reggio, S. Severina, and Otranto, they introduced the Nomocanon in Fourteen Titles, the Nomocanon in Fifty Titles, and the Synopsis of Canons to serve as legal reference works. It then focuses on the Carbone nomocanon (Vat. gr. 1980–1981), the only complete nomocanon to survive from the era of Byzantine rule, arguing that it was probably produced in the eleventh century for use by a Greek bishop in Lucania. The manuscript’s contents and marginalia indicate that its owner was fully aligned with the legal system of Constantinople and show no influences from neighbouring Latin jurisdictions. Finally, the chapter looks at evidence from the period of Norman conquest in the late eleventh century, revealing how the resulting tensions between Latin and Greek Christians in the region left traces of contemporary Byzantine polemic against the azyma (unleavened bread in the Eucharist) in Calabrian nomocanons of the twelfth century.