Can elites use cosmological imagery to sanction marital and slavery practices for their political aspirations? Can interactions between Late Antique legal systems be thought beyond "borrowings?" This work studies legal writings from the Zoroastrian, East Syrian, and Islamic traditions arguing that Late Antique matrimonial and slavery practices were significantly informed by cosmological imagery and repeatedly brought in line with the elites' political aspirations. It suggests that these legal traditions should be thought in a shared epistemic framework to account for the changes and meaningfulness of legal concepts and institutions and cannot simply be reduced to a narrative of borrowings. Instead, this book shows that interactions between Late Antique legal systems were more complex and characterized by patterns of negotiation and competition mirroring the various entanglements of the Late Antique citizen's life.