The article examines the enduring phenomenon of double monasticism, the type of religious organization whereby a single monastic unit combined a male and a female community that followed the same rule, recognized the authority of the same superior, and functioned within the boundaries of the same monastic compound or in close proximity to each other, but not in shared quarters. After centuries of evolution since late antiquity, double monasteries effectively ceased to exist in the Latin West by the high middle ages, but demonstrated remarkable staying powers in the sphere of historic Byzantine cultural influences, particularly in Orthodox Eastern Europe and Christian Middle East, where this archaic type of monastic institution survived into the eighteenth and nineteenth centuries. Based on previously unexplored archival material from the Orthodox lands of the Polish–Lithuanian Commonwealth and later the Ukrainian Hetmanate, a semi-autonomous state ruled by elective officers who recognized the tsar of Muscovy as their suzerain, the article analyses the place of kinship structures, economic and political factors, legal frameworks, and the role of the imperial state in the evolution and ultimate decline of the double monastery.