Following the collapse of the Republic, laws pertaining to marriage, parenting, and adultery were part of Augustus' program to restore the "mos maiorum" (traditional social norms), while consolidating his power as princeps and "paterfamilias" of the Roman state. Marriage and remarriage had become less frequent; and the citizen birth-rate had fallen, particularly among the wealthier, more leisured classes. Augustan law pertaining to marriage and family life encouraged marriage and having children, and punished adultery as a crime. The new legislation formalized and enforced what had been considered a traditional, moral duty to family and the State; all men between 25 and 60 years of age, and all women between 20 and 50 were to marry and have children, or pay extra tax in proportion to their wealth. Members of the upper classes thus had most to lose. Citizens who had already produced three children, and freed persons who had produced four, were exempt. Marriages between senators and freed women, and slaves and citizens, were declared legally void. Children born to such liaisons were illegitimate, non-citizen and unable to inherit.