Marriage in the premodern world was rarely just a personal promise — it was a binding economic contract, and every civilization built its own machinery to secure it. In medieval Europe, two separate flows of property moved in opposite directions: the dowry (dos), rooted in Roman law, travelled from the bride's family to the groom, while dower — which grew out of an older Germanic custom and was spread across Western Europe partly through the Church's influence — obligated the husband's side to set aside a life-interest in land (one third, under English law) to support the wife if she outlived him. Both were serious enough to appear in King Philip Augustus's 1214 ordinance and in Magna Carta itself in 1215. In the Islamic world, the logic ran in a single, mandatory direction: the mahr was paid by the groom directly to the bride — not to her father or guardian — and a hadith in Sahih al-Bukhari holds that a marriage without it is void. Mahr was commonly split into a prompt portion paid at the wedding and a deferred portion that became a debt owed to the wife, payable on divorce or the husband's death, functioning almost like built-in alimony. In China, the exchange ran through the family's six ritual steps (六禮) codified by the Zhou dynasty: the groom's family sent betrothal gifts (聘禮) to the bride's family to seal the match, while the bride's own family sent her off with a dowry (嫁妝) that, especially from the Song dynasty onward, became an increasingly visible marker of status — and remained, at least in principle, her own property. Three civilizations, three different answers to one question: when a marriage ends, by death or by divorce, who is left holding the security?