The Private International Law rule to the effect that where there is no antenuptial contract the proprietary consequences of a marriage are determined by the husband's domiciliary law at the time of the marriage was, for the first time, the subject of legal arguments before the Court of Appeal in the case of Mtui v. Mtui. Under South African law, the law selected by this rule applies to all property of the spouses, whether acquired before or after the marriage, and whether movable or immovable. Furthermore, the domiciliary law determines the law applicable to the proprietary consequences of the marriage once and for all because of the immutability doctrine of Roman-Dutch law and will be the lex causae whenever questions concerning the property relations of the spouses arise.