Justinian I (527–65) is widely regarded as one of the most significant figures in Roman and Byzantine history, not least due to his ambitious codification of Roman law. The Justinianic legal corpus—comprising the Code, Digest, Institutes, and Novels—represents a comprehensive legal framework. Among these were numerous provisions concerning eunuchs and male infertility, indicating official concern with their legal status. These laws offer invaluable insights into the social and legal treatment of eunuchs in the later Roman world. Following Justinian’s death, the empire underwent substantial transformation, particularly in the wake of seventh-century Islamic conquests. This reshaped civil, military, economic, and legal institutions. The Ecloga, issued in 741 under Leo III and Constantine V, represents the first major post-Justinian legal compilation. While drawing on Justinianic law, it notably omits the earlier provisions on eunuchs. This chapter compares the legal framework of Justinian’s era with that of the eighth century, focusing on how eunuchs were legally defined and treated. The chapter shows that the character and context of the Ecloga, which reflected imperial needs and policies in the eighth century, provides an explanation of the situation surrounding the laws about eunuchs.