Basque customs in the Old Regime dictated the traditional succession rules of aînesse intégrale, which entitled the first-born male or female child to inherit all family assets (house and land) upon marriage. He or she was then to cohabit with the parents as a stem family, thus securing the transition and continuity of the house. With the implementation of the Civil Code in the 19th century, these ancient succession practices were abolished, forcing families to partition their assets equally among their children. Family reconstitution, succession records, and land registers of the 19th century indicate that, despite the new law, Basque families circumvented the law to transmit their property to one child, thus avoiding partitioning and securing continuity of the house. To perpetuate their ancient succession practices, families elaborated new strategies, showing flexibility toward traditional practices (especially aînesse intégrale) and making concessions to the heir or heiress, spouse, and siblings. They adapted the customs to the new law while maintaining the most essential prerogatives of ancient family traditions (single inheritance) for the survival of the bhouse systemQ. D