The entire legal system of the Roman empire continued on into the Byzantine period with only minor modifications. This included both civil law and criminal law. One set of laws that were continuous from the Augustan period to the Byzantine were those pertaining to the family. In these laws, slaves, sons who had not been emancipated, and wives under one of two types of marriage were in patria potestas and had no legal existence independent of the pater familas but were extensions of his will. Women who had born 3 living children could act for themselves in legal cases under the ius tres liberorum.