The late antique tradition often portrays a polemically distorted image of the emperor's chief chamberlain, characterized by the rejection of a societal outsider, namely a eunuch. Based on a prosopographical study, the formal structures of the office, as well as the functions and competencies of the praepositus sacri cubiculi, are explained in detail. The assessment of the office holder's social position, also measured by sociological criteria in light of late antique values, contributes to the understanding of the efficiency of an institutional court eunuch. The history of the office and its political and social significance in the 4th and 5th centuries provides insight into late antique governance and administrative practices.