Until the late 20th century, married women's rights remained restricted by law. The family law has changed gradually throughout the 20th century, with white women being the first to gain rights, and black women in customary marriages being the last. Marriage law has, for most of the 20th century, been based on the Roman-Dutch law concept of marital power of the husband, a doctrine in terms of which a wife was legally an incapax under the usufructory tutorship (tutela usufructuaria) of her husband.